## Monday, June 16, 2008

### USPC 2008 wrapup

Edit: score update

I was a little worried going into this year's competition, given the quantity of grid-based puzzles (black pearl, arrow ring, masyu, kuromasu, fences, corral, etc.). I had tried practicing using last year's Masyu (which I almost completed in time last year), but ended up wasting a lot of time trying to work it out.

Anyway, this year I felt a lot better on my time management. Initially, I thought maybe I shouldn't have spent so much time on KakurOh or Ampers& Crisscross without getting any solutions and instead focused on fences, but I ended up taking way too much time to complete fences after the contest was over, so I think some of the harder difficulty puzzles of that time end up eating a lot of my time.

Battleships was straightforward, as was Sudoku. I probably lost some time on Sudoku with a guess in the middle that didn't pan out, after which I had to start over, since I didn't distinguish my guesses from my solves like I normally do using pen vs. pencil.

Sum figure was pretty quick, given the quick constraints on 10 and 30. That leaves 10 as either 0 1 3 6 or 0 1 2 7. Heuristically, these should probably be placed according to the size of the sum they need to be in, which worked out well.

Arrow ring was also reasonably quick, since all my guesses turned out to be correct. I think this is one of those puzzles where my heuristic approach yields some really good results. I practiced on last year's arrow ring to great success, so I think I can try a looser strategy next time to gain back some time.

Double feature was rather nice this time, as I figured out the differences much faster.

Black Pearl was a quick solve, but I made two major screwups. First, I misinterpreted the directions for answer submission, and counted the lengths of the paths between all 1's in the sequence. The diagram doesn't differentiate between this interpretation and the actual answer format. Then I miscounted, which is unfortunate, since otherwise I might have been able to request some points back. My solution (in diagram form) is correct, though.

Masyu was much quicker this time, because of the increased number of constraints.

Nebijok was a standard puzzle type that went pretty well.

I didn't try Number Blocks until late in the contest, since usually I'm bad at the math ones, but this one was very open to a successful attack. The first puzzle, heuristically should have the 3 24's as the bottom sum and the two large products. This quickly yields most of the digits. The second puzzle also worked nicely, since the product has to be 1 x 2 x 8, and 8 is the only number that will work for the top row. The rest fell into place quickly after that.

I didn't try Kuromasu, it seemed very corral-esque to me, and I suck at corral.

Murder No. 6 was fun. It was slow going at first, but picked up speed quickly. As mentioned by others, the 15's and 14's and even the occasional 13 helped a lot.

Obviously I skipped Corral as well.

Tilted Weights I didn't bother trying as I usually suck at these, although a glance after the contest suggests that it should be quickly solved. The bottom two balances are pretty well constrained, and to balance the overall puzzle, the leftmost balance needs to be two relatively large consecutive numbers.

Distances also seemed too close to Corral for comfort.

Dot Triangles looked pretty impossible, and given Tom Snyder's reaction to it, I think skipping it was an excellent choice.

Crisscross Pairs worked out nicely. I think there are probably some faster methods (such as focusing on the rings rather than the 4th vertical word which has more constraints.)

Fences I almost got near the end. All but the bottom-right corner worked out quickly, and it was just a matter of trying to get the middle worked out, while keeping all the sheep on the same side of the fence. I ended up solving this after the contest after maybe 30 minutes due to a number of mistakes and lack of time pressure at that point.

SuDON'Tku is one I probably should have worked harder on. I only spent a few minutes, made a mistake, and decided it could be very risky to continue to try this puzzle given the number of mistakes I might make. I tried it a little bit after the contest and made more mistakes, but eventually figured out the strategy, so I think I should be pretty quick now.

I wasted a lot of time on KakurOh, only getting about 1/6 of the puzzle. There are generally fewer quick logic-solves in the beginning for these harder KakurOh's, which is something I'm not used to, I think. Either that, or I missed some vital clues.

Ampers& Crisscross is something I also should've gotten. I had an initial guess that didn't pan out, but that was probably because I was taking a more local strategy for this (which works well for me in other crisscrosses). I think the approach of working out the rings is probably the quickest, since that gives many more constraints on the connecting words and ring location.

Total Solved Points: 150 145 (Um, it's a good thing I can add correctly during the competition?)
Likely Resulting Points: 135 (-10 incorrect Black Pearl answer, -5 incorrect answer penalty) 145 (SOMEHOW, they gave me credit for Black Pearl, EVEN THOUGH I made the mistakes in submission above (and also dropped a comma apparently).

Improvement over last year: LOTS.

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