motris

The Chronicle of Higher Education has a brief story today, but it was the story that had the most interesting photoshoot done for the article by a free-lance Bay Area photographer, Alison Yin.

( Read more... )

While the number of interviews I have been doing in the last two weeks is less than after the Philly US Sudoku Championship, the quality of some of the coverage has been very good. I already linked to my first real video piece, from KGO-TV here in SF. Its still saved in HD on my DVR.

Today, the San Jose Mercury News has a front page piece about me. My parents won't agree, but I'm so used to seeing the Synder construction that I can forgive the two typos in the course of the story for what is a really well-written account of my life in puzzles and what I hope to accomplish as an individual. The best addition to the ongoing story though may be the extra online video that creatively displays a sea of numbers at different times by merging video of me solving on paper and on computer. Definitely worth a quick peak.

Outside of those stories, a couple magazine pieces will be forthcoming and I've also had at least one other "creative" photo-shoot that I can't wait to see the results from.

I'm behind in my blogging (I particularly mean to write up more thoughts on Coed Astronomy's BAAG before this weekend's Shinteki event further adds to the puzzlehunt backlog, and also post some more after-thoughts about the WSC), but I've begun my USPC training. For the next month, I will only solve sudoku where required in an actual test, as I try to get back to full speed on other puzzle types. I've decided one thing I will do is retake all the available US practice tests to get a sense of my current speed and my current point/minute bests and worsts. This recording here is meant more for me to remember in future years, but some readers will undoubtedly want some measuring stick to compare against although I must say its a difficult measuring stick to use.

Today, I did the 2001 qualifying test.
( Read more... )

So I always have a busy week after returning from a world puzzle/sudoku championship - catching up on work, mail (snail and electronic), DVRed shows, .... After sudoku events, there is often a bunch of interviews. This year, I chose to give a sudoku lecture to the BioEngineering students - an even more fleshed out form of my "Art of Sudoku" talk from Silicon Valley Puzzle Day - and I think that went really well. A local ABC news crew was filming a story about me that morning and filmed a bit of the talk too.


While I'm still in a sudoku free-zone (unless its needed on camera, I guess, for a story), I participated in a great puzzle hunt in San Francisco today put on by Coed Astronomy. My team - "Blind and Draggin'" was a grouping of the Grahams from the five blind boys and two of here be dragons with Dr. Sudoku being the glue. The puzzles were great and uniformly elegant, there was a really solid meta, and I am quickly learning how much I prefer the Bay area scene to events held elsewhere. You see all the puzzles, you are always solving as a team, you can oftentimes sense if you are behind/ahead, .... Our team did finish first, even using the "crazy" level of clues, but the event was run over two weekends and not truly a competition so the result doesn't matter. I'll write up a full report on the hunt sometime in the future highlighting basically all the puzzles as they were all really nice.

( Read more... )

This one is goa-ing to be long, so I'll put it behind that friendly lj-cut.

( Read more... )

I'm going to try to post my WSC report soon (I've set aside this evening to do most of the writing, but they tend to get long). I'll probably split my retelling of the event from some philosophical points about sudoku competitions, which may make it easier to make my midnight deadline goal.

Anyway, I came back to the US with the nice surprise that my battleship sudoku made their way into GAMES. Since this is the magazine I first learned to love puzzles with (Battleships, specifically), it is nice that my combination of battleship and sudoku found a home in their July issue. It also was a particularly nice surprise as, while I had asked my publisher to suggest them to GAMES since they publish Sterling puzzles there from time to time, I had never heard that the spread was accepted so it was indeed news even to me.

All of the puzzles come from my book, so if you got to this entry by searching "Battleship Sudoku" and "GAMES" and want to know more about the puzzle, get that book. You can also find past examples of battleship sudoku and other sudoku variations by clicking over to my written puzzles page.

I hate plane travel and in both directions for this WSC my trips were not uneventful. That about 65% of the time this trip was going towards, being in, or flying between airports suggests how little sleep I got so it may be a couple days before I get my extra long super spicy Goa trip report up (or even wake up).

Still, my bags surviving both passes through the new Terminal 5 at Heathrow was the one saving grace of the flights.

I've never used the word before, but "w00t!"

Okay, technically I tried to use the word before, but showed my complete unhipness by spelling it without numb3rs.

So, while ~40 hours of travel await before I can get home, I can announce once again that I am world sudoku champion. The official site does not list the results, but the individual competition was a very tight race between myself and Jakub Ondrousek. He blazed through the classic rounds bonus-wise while I could not bank a lot of bonus as the variant rounds had none. He and I were the sole finishers of round 2 with him about 5 minutes faster. His relay round time though gave him a ridiculous 12 minutes of bonus points which carried him slightly over me for the top individual placement entering the playoffs. Still, the two of us were significantly separated from the field with Yuhei Kusui from Japan in third. As I predicted, in a championship with strong scoring biases towards classics, all 4 "classics trophy" players were in the top 8 (1,2,4,7). We went through long playoff rounds (that continued to be adapted seemingly on the fly in an unsettling way - we first got a list with 3 puzzles in the 3 rounds, then it suddenly became 4 before they started. We had semifinal/final/classics final listed on the page but they ran it semifinal/classics final/final.

So, anyway, after struggling with jet lag and round and round of puzzles I broke but perservering to have a solid qualification, I pulled out two stellar finals rounds where it mattered on stage under the cameras and won both titles, hopefully putting to rest the need to run two "separate" championships. I appreciate having classics more represented in the competition, but the sad truth of classics puzzles is that if you make them very hard, competitors will go to the "nuclear option" of bifurcation to solve them fastest. I like poker and roshambo as much as the next person, but a sudoku tournament should test skill not luck and so the hardest classic in the playoffs being a total guess-fest was silly.

Negatives aside, the puzzles were excellent, many were incredible with artistic themes and beautiful solving themes. I'll enjoy solving them slower soon.

Still waiting for the official instruction booklet which will tell us about bonuses and timing but the preview of puzzle types already posted on wsc2008.com suggests the kind of championship we will see. I'm glad to finally see a sudoku relay round in the event, with the 7th (classics) round having that characteristic. There is a large round of "twins" puzzles which will hopefully have some good puzzles. I tend to dislike the "copy a solution from here to there" steps when they arise, and this seems to at least have one chance at that in the alphabetic substitution puzzle, but the others are a bit unusual, particularly the sum >8 and difference 1/8 twins. The rest of the rounds seem standard fare now for the third WSC - variants and classics spread around in reasonably long rounds where I tend to be in the top of the field consistently. I've solved basically all the types before so nothing really new to brainstorm this year compared with all the geometric variants last year that had "hidden" constraints you could prove by playing with the examples.

The team rounds seem somewhat "standard" still as team rounds go but may allow a little more teamwork than last year's. Part 9 has three puzzles split into pieces and, with three people, we will obviously each take one puzzle for the tiled sum/irregular/diagonal. I understand how you'd tile a diagonal sudoku and I guess a tiled irregular is probably just a normal jigsaw-like puzzle (play with the arrangement of pieces until you get a 9x9 square) but I'm curious to see how you tile a sum sudoku. The other team round is a weakest link round with a samurai puzzle but until I see the instructions, its not clear what the "entry" puzzle(s) will be to the team desk. Only three members of our group of four are on the team and the decision of who is on the team has not yet been made. We have a talented squad, so some on-site brainstorming will need to be done to make this decision.

The biggest apparent news in the championship is the presence of two titles for the individuals, with it seeming that without winning both, either title itself is somewhat diminished. This means I have a lot more to shoot for as I defend my title this year. I'm tired of the criticism that the WSC champion is good at variants and not classic puzzles. I won the US championship handily with just classics and I will hopefully do well in Goa as well.

If there is a theme to my championship thinking then, it is that I will be taking it to 11. With that in mind, here is a new Tablecloth Sudoku (the type created at WSC2) of the Spinal Tap variety (11 wide with 9x9 sudoku in the middle). All rows/columns will contain 1-9 and A,B and no digit/letter is repeated in the 3x3 bold regions in the center. The big shapes belong to multiple rows/columns. This is an easy example but it proves the larger size is possible.

This weekend marked my official entry into the Bay Area puzzle scene as I competed in my first game with the Five Blind Boys, a team with some friends I met during the National Treasure Clue Hunt several months ago. By adding on me and nickbaxter for this Game, a strong team had seemingly gotten stronger. While they don't really count records in these things, we did end up finishing first, about a half hour ahead of the Burninators who were the next closest team that wasn't "skipped" ahead a clue during the course of the hunt.

The event was themed around Midnight Madness, a 1980 Disney film featuring an all-night puzzle hunt that is most notable as being the theatrical debut of Michael J. Fox in a supporting role as a whiny brother. As far as puzzle hunt theming goes, this event had it in spades. The film passes through a set of locations in LA (Griffith Park Observatory, a piano factory, a brewery, a restaurant, a miniature golf course, LAX, a video arcade, and finally the Bonaventure hotel) and this hunt found locations between Palo Alto and San Jose that could match up for all of those places. This certainly took a lot of effort, as getting a whole golf course to stay open hours after its normal closing so twenty-some teams could search around its holes at 2 AM cannot be a simple (or cheap) thing to do. Along the lines of the movie, the clues also all tended to be "old school"; while this often led to clues that were difficult to decipher without hinting, it did mean that clues were not forced to use Morse or Braille or Semaphore as a Midnight Madness hunt should not need a code sheet.

In addition to stellar theming (that reached its humorous peak after hitchhiking at 3 mph with an old couple that wouldn't stop talking), there were a couple really stellar clues. To match the 8800 keys from the movie, we went to a house with 88x keys - probably seven different electronic keyboards - and given a set of scores to what turned out to be commercial jingles. In addition to identifying what the jingles were by playing them, we found each had an incorrect note. Extracting those incorrect notes and placing them in alphabetical order by jingle gave us another jingle which was for an item we were meant to ask for at the Bar. It was a well executed puzzle and given our team's ability to both play music and identify themes, we got through it rather efficiently. The "airport" clues were actually at several locations as we first had a difficult radio clue, then a set of papers handed to us by Hare Krishnas, then a set of LOLcat pictures found in a locker of sorts. The Hare Krishna clue, which most teams were skipped over, was another one I rather enjoyed. It involved a biblical essay that had tons of typos. Except, while most typos were on all the copies we had, there were some changes, particularly in the middle of the document, that changed on what turned out to be 4 different copies. The "chast virjin" [sic] became a "phaste virjin" [sic] and so on. I figured we should map out where all the different errors were on a single sheet and shading in those incorrect places drew a picture of a greyhound, the logo for a nearby bus station. Really well executed clue in my opinion. The LOLcats clue involved us finding an order to the photos by making a word chain, and then using some editing marks to extract more normal english letters from LOLcat speak. From there we were off to an arcade where a modified version of Star Fire, the video game played in the movie, was waiting for us. It was fun to try to figure out how to break this game as other teams at other computers/tvs were trying to as well. Several teams figured it out rather close together to set up a race back to Stanford for some final clues.

These last clues were also really good (which made my feelings ending the hunt much better than during the middle when the clues were not agreeing with me as much). We had a quick game of seemingly "infinite color" mastermind as we had to figure out how to get a teammate in a hissy fit back. Giving him 4 word phrases would elicit a particular response. We figured out we were doing mastermind, but took forever to figure out the 4 words we needed, particularly after we got to the "[teammate's name], you are _____" part of the clue. After lots of reasonable adjectives, and a lot of unreasonable ones, we got the one we needed to reach the final event. Here, lagging teams were again jumped ahead to engage in a game of kick-ball of sorts on the Oval lawn at Stanford. 6 large blown-up balls that looked like volleyballs were on the field with red and black words written on each of them. You needed to gather those words, but to do so you needed to venture on the field to move the balls/read what was on them. On the field were members of GC holding air hammers to try to hit you. If you got tagged by a hammer, you had to return to the sideline. Needless to say, as I have good vision and could read from the sidelines, I was doing all the data collection while others ran onto the field. It lasted awhile until the balls started popping, and then the character of the "game" on the field changed. Still, we got almost all the words and went to the solving part. The puzzle involved a total of 84 words, 12 total sets of 7 that belonged in groups (like Bond Films, or Elements, or Monopoly Spaces, ...) but each group, when placed in a natural order, had a missing member from what would have been a grouping of 8 consecutive items. We got the groupings easily once we had all the words, but also quickly saw how to order the groups to read out the location of the finish line.

Overall, while there were some definite moments of pain with some hard clues with seemingly too many possibilities to work with, there were several memorable puzzles in this 15-hour game and for my first one as a participant, I felt I contributed a lot. My team was great, and I hope to compete with many of them again, even if I am still considering myself a "free agent" for future events. Thanks to Snout for putting on a fun night of Midnight Madness. Now, to catch up on sleep and get ready for Goa.

Having downloaded the free April Fool's DLC for Rock Band, I decided to actually find a couple hours to sit down and play through Portal so that I could appreciate what the song meant. It was a good 2.5-3 hours or so, but seemingly a bit short and easy to me. Have to go back and do all the specific challenges still, but the pay-off at the end was incredibly worth it.

wsc2008.com finally got updated with content. The types of puzzles will be officially released on Monday and the instruction booklet with rounds/point breakdown on Thursday, but we already have a hint that this championship will be a bit different than the first two WSC events. It seems from my reading of the site that there will be no playoff in determining the "World Sudoku Champion" - just a total score over all rounds including those with variants - but that a separate title specific to classic sudoku will be determined with a final playoff. Two rounds of just classic sudoku during the WSC will determine who competes in that playoff. I'm really unsure how I feel about this (it means I have two things to win now, not just one, and makes the reporting job for the press difficult), but we'll see if the structure is as I am interpreting it when the final rules are released on Thursday. Still, I have been focusing on classic sudoku improvements this last year and should be competitive in any format they throw at us.

Otherwise, been tearing through tons of sudoku in my free time as I prepare for the championship. Nikoli.com put up a fun Botsu Bako puzzle today. Just like the earlier Q puzzle at the US Sudoku Championship, it takes some creative imagination of a placement or two to see how to do it, but I was somewhat happy with my ~10:30 time. On paper this would have been much faster as I would have entered a focused T&E mode early on, which is unfortunate as it is a very nice puzzle but, like most sudoku, guessing will beat logic timewise for the really hard ones.

So there have been a couple times that the misuse of language has inspired a puzzle and this entry will represent another such case.

( Read more... )

As I count down to Battleship Sudoku's official release on April 1 (even though Amazon.com is already shipping copies and they may already be popping up in stores), this week I am also celebrating the news that my second book idea has been approved and you will likely see at least one more title from Sterling containing my original puzzles in the future.

This week's new design - Linked Shape Sudoku - was an idea that arose while I was first brainstorming puzzles for a book of new sudoku variations. While it was ultimately a concept a bit too challenging to include in that project without further tweaking, it is still a puzzle that readers of this blog will hopefully enjoy. This variant features a concept that arises in Battleship Sudoku where linking sets of numbers (in the context of boats) make digit placements much more interesting than in the classic sudoku form as you must consider multiple columns/rows at a time. Here, that concept is jacked up to ~11 as you have to work through different contingencies of placements between shapes in two sudoku grids. The puzzle is difficult.




Linked Shape Sudoku:

Fill in the digits 1 to 9 a single time in each row, column, and 3x3 box in the two grids below. There are some shaded shapes in the two grids. There are no constraints on what digits can be used in each shape. However, the identity and location of digits in each shape must be the same for both two puzzles, allowing for ROTATION AND/OR REFLECTION of the shapes where possible. For example, if the long 4x1 tetromino is 5678 from left to right in the top grid, it can be 5678 or 8765 from left to right in the bottom grid as a result of rotation. There is one solution to this set of two grids which can be found by logic alone.


Forecast: Scorching Heat

For the last Stanford puzzle, which I believe is as hard as 7 or possibly harder, I pulled out a ridiculous time. See how you compare.



Solution of Puzzle #8 - 2 minutes, 9 seconds

Puzzle #8 explanation

Continuing my four-week series of new puzzle types leading up to the release of Battleship Sudoku, with week one being the introduction of Color Sudoku as a fun new sudoku variant, here is week two: irakAkari.

I loves me some nikoli puzzles but have rarely tried to tweak any of their non-sudoku types until now. Akari (rules for Akari) is a "puzzle" that works much better online than on paper, but suffers I feel from most often being too easy. The 10x10 puzzles on Nikoli.com feel a lot like a sudoku might if you get 72 givens - you basically just have to do a couple obvious things like click all four squares around a "4" and then you are done. They become speed races for that 5-6 second solution, and while the larger puzzles can have more interesting chaining at times, it seems Akari could be made much more interesting with some small changes. Certainly, going to a non-square board might improve the puzzle as hexagonal grids offer a lot more potential for block-to-block communication in the puzzle. I leave this construction as an exercise to the reader for now. However, I've wondered in the square puzzle if a method to extend viewing zones from vertical/horizontal lines into lines that bend could be interesting.

Thematically, if the puzzle is about placing guards in a museum so that they collectively "see" every square but see no other guards, imagine the museum now is made entirely of mirrors. This means in most directions the guards will see themselves (still allowed), but if there are diagonal walls, then the viewing zone will extend in a new direction allowing a guard to see another guard around a corner, which is not allowed. In this variation, all squares, including squares containing a diagonal mirror, are still seen. However, guards CANNOT occupy a square with a diagonal mirror, so these spots must all be viewed from elsewhere. Numbers on black squares, as always, represent the number of guards immediately adjacent to that square.

The example should give you a feel for how a solution could look. I've then given 3 puzzles that are maybe medium in difficulty, and definitely harder as small puzzles than regular Akari, that hopefully show off the potentials for interesting logical deductions with this small change.


irakAkari example:







Puzzle 1 (Breezy)






Puzzle 2 (Gusts up to 25 mph)






Puzzle 3 (Storm warning)

Two more puzzles to go; here is #7 of 8 in the Stanford Medicine Sudoku series. I completed this puzzle in 3'25" and I like to think that I purposefully filled in one of the easiest digits last. Still, there are many ways to approach a puzzle and just looking at certain digits is not where I get started here as you'll hear in the discussion video.



Solution of Puzzle #7 - 3 minute, 25 seconds

Puzzle #7 explanation


In other sudoku news, I took the weekend to retake some past championships (specifically WSC1, 2, and last year's French and Japanese championships - two countries who did not run a championship this year despite good tests last year). I wanted to answer two questions and got about one and a half answers out. First, I need exactly 2.3 of me to complete the team rounds from Prague, taking an average of 2 hours and 17 minutes over those two rounds. This coming WSC will feature smaller teams so maybe I can have a bigger role in helping the team reach 1st place, but then again we did really really well on the team rounds in Prague and just had too big of a gap in the individual results to catch up. My favorite puzzle from that WSC this go-around is probably the even in the second team round which has a very nice work-in (even without using uniqueness which is not enough). My second question was, given my famous "15-20% better" statement of last year between WSC 1 and WSC 2, what would my x% improvement be this year. I'd say I'm 15-20% faster at classics, which are the most important for the US championship, but the WSC puzzles are much more varied so my real improvement is not as high as last year, maybe 5-10%. Let's hope it is enough to stay in a comfortable play-off position.

Earlier this week I got an author's copy of Battleship Sudoku. To build excitement for this book that I can now see is real and about to be published, I've decided to start posting some new puzzle ideas each week until the time of the release of the book. So, without further ado, here is a kind of sudoku I've had in mind since before Mystery Hunt 2007. It got turned in part into my color maze (Splits and Mergers) since I couldn't do it as a sudoku in that Hunt, but colors are a great gimmick to work with in so many different kinds of overlayed puzzles. I actually wrote these last summer while at a chemistry conference at Duke, about the same time as the Mastermindoku, so these have been on the shelf for far too long for such a fun idea.


Color Sudoku:
Solve the following sets of 3 puzzles using the given clues. The puzzles themselves are red, yellow, and blue, and the clues you receive may be in these primary colors, in the secondary colors (orange, purple, green), or in the color black. A number in a secondary color represents the sum of the two digits in the corresponding puzzles (green 4 could mean yellow 1 + blue 3) while a number in black represents the sum over all three puzzles (black 7 could mean red 1 + yellow 2 + blue 4). The standard sudoku rules of 1 to 6 in each row/column/box apply, but NO NUMBER IS REPEATED in the same place in two puzzles. A green 4 cannot mean yellow 2 + blue 2 as this would have two 2's in the same cell.

As the only examples of this puzzle type, it might seem odd to already be burying themes in them, but this is how I work. There are some good graphical themes in the form of rainbow colorings in the first two, and a secret "meta"-like theme in the last. If you can give me a clear, succinct identification and rationale behind my favorite color, you win. Enjoy (at least until next week's new puzzles).



Puzzle 1 (Bright Sunny Day)







Puzzle 2 (Serious Rain)







Puzzle 3 (Some Showers Early, Then Clearing)

Week six of the sudoku series is up and while this will be my slowest week for the 8-part series, it is not the hardest puzzle. That happens sometimes. I do an okay job in the explanation video of focusing on certain regions in the puzzle once I fill them in. Here that gives you a lot of quick progress. My real problem though is sometimes writing too many digits too fast and then not knowing where to find the trail again. I at least see a critical row I could finish in the solving video for awhile but don't look at. There are only two digits left in it, so it is a great place to at least check if you can fill it in, if not write down in some fashion the numbers that are shared in it.

Puzzle #6 - by Wei-Hwa Huang


Solution of Puzzle #6 - 3 minute, 36 seconds

Puzzle #6 explanation


Two other pieces of sudoku business:

First, courtesy of thepiemansimon, I have completed the UK qualifying test. The first round had five difficult puzzles (including one nasty classic and one nasty diagonal) and took me 46 minutes. The latter round had twenty-four puzzles with none of them being particularly hard and took me 1h 22.2 minutes. This is just a hair over two-thirds of the time for a perfect score so again I meet my prequalifier goal of perfect score under time. Its odd to set a standard of hard puzzles on the round that limits participation (and which may encourage online solving tools as they were real nasty) and then to go to easier puzzles in the second step after you may have already chosen for something other than legitimate fast solvers. I hope Puzzler eventually posts it online for others to see, if just because some of the nations with the best qualifiers last year (France, Japan) are not doing qualifiers this year. My next practice tests may be the Russian from this year, as well as redoing the WSC1 and WSC2 puzzles.

Second, tied to their qualification apparently, the Slovak championship set a "world record" in sudoku of 5:25 and I only found out about this as someone felt it important enough to put on wikipedia. I cannot find this puzzle, which I am dying to see and solve in under 4 minutes, but I wanted to point out I already have two "world records" in sudoku so this is no new feat as the wikipedia competition section suggests. Also, without solving about twenty puzzles at one difficulty rating (which must be standardized by software), I'm not convinced any record is meaningful. If this is just the best time on one puzzle that is "hard", then I bet having ten more attempts at it would greatly improve the time for that whole room of competitors.

I participated in Lost: The Game on Stanford's campus this weekend, a puzzle hunt designed by some Stanford students. It was my first experience captaining a team and while my friends were not terribly experienced with puzzle-solving, we did rather well IMO finishing all the puzzles and the meta before the event ended. There was a very close call where we found a clue in a library literally seconds before the librarian was going to escort us out as the library was closed. There was also a fair bit of biking and a fair bit of searching for where clues were hidden and while I have a couple gripes about some answer messages being unnecessarily complicated, game control was very good throughout the event at nudging through the difficulties.


There were some standout puzzles and activities. I really liked a "simple" puzzle that involved a game of mastermind with countries.

List 1: Lithuania (2 black), Sierra Leone (2 white), Austria (1 white, 1 black).
List 2: Ghana (1 white, 1 black), Gabon (2 white), Russia (2 white).

Eventually you take (1,first), (1, last), (2, fourth), (2, last) for the location on campus.


There was also a good example of a typical Hunt-style puzzle "Odd One Odd One Out" where you get list of words with some characteristic that works for all of them except one member doesn't fit. Those extraneous words eventually form secondary sets that had the same principle at play. Some of the choices were creative (and at least new to me) even if I'd seen the basic type before and knew what to do. What I liked most about this kind of puzzle is that it let our whole team contribute in getting some of the wackier ones. One of the second layer steps that I got was a list where all the words but one could be typed with exclusively the right hand on the keyboard (the other word exclusively with the left hand). Other cute ones included the list "pink, silver, orange, purple" which on its surface nicely represents colors but in actuality is representing some other property that only three of the four have.

There was also a maze-puzzle using the Clark Center, the building where I work, so now I don't need to go about writing a puzzle for this location on campus. It has all its hallways and about 8 sets of stairs outside, so the organizers had put together a grid layout imposed over the 3 floors of the building that we needed to draw a non-intersecting loop through. Traveling this course then gave you letters that had been written on the ground in chalk. The message was awkward and we needed much nudging, but I plan to run "Clark Center repeats" in upcoming exercise days just for kicks.

The best environmental puzzle though, that fit perfectly with the Lost theme, involved finding a compass in a garden and then traveling "north" with the compass down this alleyway. In the middle you passed a magnetic spectroscopy building with an uber-strong magnet. As my team is continuing north, I'm trying to tell them to stop without alerting the other teams exploring the area that something is "wrong" with the compass. The needle is now pointing decidedly east at this building. We got to explore the outside of this building, seeing horribly bent bars of metal and spoons and so on that demonstrated the force of this magnetic field, and after much fun discovery on and around the building, eventually found the clue. Given the importance of magnetism in Lost, this was a very excellent place to hide a clue and will be the most memorable part of this Game to me.

Two more weeks of puzzles are now up on Youtube. Unfortunately, a camera problem in week 4 prevented the camera shooting my answer paper from being used so that solving video is not useful as you can't see what I'm writing. We'd also discussed using the paper shot more in my discussion videos for the last half of the series and while that could not be done in week 4 for the same technical reason, it will be done for weeks 5 through 8. However, don't ignore the week 4 puzzle as it is the most beautiful of Wei-Hwa's puzzles that we are using in this series, with a nice exploration of a diagonal theme of a blown-up 123456789 standard box. I discuss this explicitly in the explanation video if you don't see what sets this apart from randomly generated puzzles.

I felt I solved Puzzle #5 a little slowly, but it has a narrow solving path and I wasn't seeing the necessary point when I solved it. It is very good practice for "pointing pairs" which make natural sense with my note system anyway.


Puzzle #4 - by Wei-Hwa Huang


Solution of Puzzle #4 - 1 minute, 43 seconds

Puzzle #4 explanation



Puzzle #5 - by Wei-Hwa Huang


Solution of Puzzle #5 - 3 minutes, 10 seconds

Puzzle #5 explanation

1. In my field, getting a publication in Nature or Science is the equivalent of hitting a home-run; a CV may be judged by the number of first author papers and such, but publishing in the top journals is also important. It is an odd feeling, therefore, to get into one of these journals because I can solve sudoku. Science (Feb. 15 issue) had a Newsmaker piece on my philly championship and upcoming title defense in Goa.

2. Just finished my annual Nikoli.com order, since the new Giants came out a couple weeks ago. Even having way too many puzzles to solve, I still sometimes feel the need to buy more even if its to get potential gift items for friends, family at the same time.

3. While 1 vs. 100 fixed some of their gameplay problems this season, making a logarithmic payout problem into a slightly more exponential one, they have really not cleaned up the end-game as now from 10 people to 0 you are stuck at a half-million dollars and have no incentive to continue. Unless EVERYONE misses from a 10+ case (which happened earlier this season), no one will ever get to the million. At least people now normally play down to the under 20 point where in the past they stopped much earlier when their marginal gains were really stuck. However, I'm still left wondering why they had to use the same mob (at least the celebrity members) every game this season and concerned about America's short-term memory when they do a dramatic reveal of how many people were wrong immediately after someone "polls the mob", polls the correct answer, and already knows how many people were right. Maybe subtraction is really hard.

4. Amnesia debuted as a new game show with one of my least favorite ranters as host. The gimmick is a contestant is asked to remember details in his/her own life for money. We hear from a parent, sibling, spouse, ..., and then there are questions on an old locker combination or sometimes trivia such as a character's name from a favorite book. It might work perfectly as a celebrity version by combining bio and trivia aspects, but with some random person as contestant, I don't know why I should care if this person wins money or not. Even Deal or No Deal tends to choose people with a more inspirational story, but the problem here is the whole show is about the person's life and unlike opening random cases or "million dollar missions", I don't get why the stories are meaningful. This show fails tremendously for me; I bet it will be very popular.

5. I just discovered the "go invisible" option in gmail's chat feature. It is an intriguing new choice to allow uninterrupted monitoring of other people's status. Not sure that I like the option, but I wonder if I'll ever be seen online in chat again.

6. Hockey season is winding down and the Sabres are scraping by near a playoff spot. The big controversy this season will likely be how the Southeast division will get a 3rd ranked playoff spot even though that team (Carolina or Washington) will be the 9th or 10th best team in the conference. Why should a crummy division get a guaranteed spot and 3rd seed? I'm not sure introducing relegation ala English football is the answer as that has bad economic incentives on teams to spend too much (and go in debt) if just to hold onto a spot in the Premiership, but we do have too many hockey clubs south of the snow belt.

Along the same lines, why should the Eastern Conference in the NBA get more than 4 playoff teams when they only have 5 teams over .500? (Note: The West, a much harder conference to play in, somehow has 10.)

My first international puzzle experience was with the tremendous US B team at the 14th WPC in Hungary where the playoff finals contained 10 puzzles at each of 10 desks. You solved a puzzle and moved up a desk or (if you could not solve it correctly or skipped it entirely) took a five minute penalty before starting the next puzzle. This seemed to work well for 9 of the 10 puzzles, as they were all somewhat easy (2-5 minute puzzles) so solving was always better than skipping. However, no one felt the 1st puzzle, a sudoku, was fair as it took everyone way too long to solve it. Wei-Hwa took somewhere around 13 minutes; Ulrich took longer, and made an error, so he lost a ton of time on it including his whole head start bonus. The smart competitors took a five minute penalty immediately. It was the big point of conversation for us in the audience, as we couldn't see any of the puzzles being solved but we could just watch when people changed desks and that first desk was the biggest obstacle for everyone.

Well, I've solved that sudoku before, and its taken me about 7-9 minutes I recall. On the first US sudoku qualifier, a rearranged version of the puzzle was used and I think I was again in the 7-9 minute range so my time to observe the necessary things (or to guess) was consistent. Well, now after more years of sudoku refinement (and a world title to defend), I tried the puzzle out again. The key placement where an X-wing reveals a naked single used to be a sticking point where I'd get paused, but not this time. 4'12"! While it took a couple years for the world to catch up in sudoku speed, all the puzzles in the Eger final are now "fair" puzzles by a measure of someone being able to solve it faster than the five minute penalty. My cumulative playoff time over those puzzles is now quite frightening, considering when I first tried it out after getting back from Eger I was well over an hour. I really think the horserace would be a cool format for a WSC playoff as well - with a range of sudoku difficulties - as opposed to the one or two shot puzzle format that has been used over the first two years. That, or a sudoku relay where the first puzzle's answer gives digits into the next one.

The puzzles are slowly creeping up in difficulty, with this the last puzzle before my "wardrobe change" (we filmed a second batch of puzzles earlier this week which will make up the last five weeks of the series). This time around, I think my approach in the discussion was a lot more thoughtful towards the solving of the puzzle than my approach during the speed race itself. Still, the solving time itself isn't so bad. The focus this time in the discussion video is on geometry, and seeing certain geometries as good points of attack in a puzzle. While this is a very obvious puzzle to target based on geometry, some others that are upcoming will point out places your eye should catch onto given patterns as well.

Puzzle #3 - by Wei-Hwa Huang


Solution Video - 2'23"

Discussion Video

As the (hopefully) last round of the online US Sudoku Championship is about to end - again featuring some of my puzzles as both easy and nasty obstacles in the way of the qualifiers - I decided to do my first warm-up championship of this year's season.

I went through the very fun Dutch championship and as is always my goal with the prequalifiers, I completed it correctly within the time - actually about 5 minutes to spare. Given this was on a black and white print-out, and I did not (as I might in competition) stop puzzles after I had the online answer criteria, this feels like a reasonably good time.

Overall, my times were:
Evensudoku - 2'19"
diagonaalsudoku - 4'27"
vormsudoku - 3'51"
trisudoku - 4'20"
flatsudoku varia - 4'43"
niet-opeenvolgende vormsudoku - 7' (once I figured out from the funky title it had a nonconsecutive constraint, it went a lot lot faster)
double killer - 4'45"
sudoku + - 10'43"
sudoku +1 - 3'46"
buttensudoku - 3'16"
flatsudoku +1 - 6'55"
sudoku varia - 11'43"
productsudoku - 6'3"
sudoku som - 9'48"