Before I say anything else about the post title, I should give a few words on my absence. In short, the outcome of the Mystery Hunt I contributed to left me very drained on puzzles for months, and I think the first time I’ve constructed anything since then was May. I think I’m finally back on my feet though. Future puzzles from me will soon be appearing at Thomas Snyder’s Grandmaster Puzzles blog. You won’t be seeing much posted at this URL anymore; probably just the occasional post like this one.
Anyways, the 2013 USPC instructions are now online. Here’s a collection of practice material on the various types. Thomas Snyder posted tips for a lot of the earlier types in a series on common USPC types; I’ll be referring to that link a few times.
1. Battleships. Print out the first page of any past USPC to get a feel for what kind of puzzle we usually see in this slot, and also check out the post from Thomas.
2. Corral. Another post from Thomas. Most old USPCs have them for practice. You can also look at the Corral category on this blog. That stretches deep into my archives though, so be warned they might be on the hard side.
3. Masyu. Another post from Thomas (on loops in general). Even if you aren’t a member, nikoli.com has some example Masyus, in case you want a feel for their style. Also check out the offerings from the USPC in 2010-2012 to see what kind of difficulty and style they often construct for this test (usually Extra by nikoli standards). If you need more, Masyu can be found in large quantities on most blogs, like mine or mathgrant’s.
4. Spot the differences. Another post from Thomas. For practice, you really want to do the spot the differences on past USPCs. The kinds of differences you usually see doesn’t change a whole lot from year to year, so just being familiar with what to look for will help a lot.
5. Pentopia. This is Bram de Laat’s type and he has posted a lot of them. This is your best bet for practice. Also check out Thomas’s post on pentomino types. If you run out of Pentopias and need more practice with a pentomino bank in general, you may want to try some of my Statue Parks, particularly those in the pentomino section of the pack. The hardest of these I’ve made require you to know the pentomino bank forwards and backwards to find a half-decent solution, so they should help with becoming more familiar with those shapes.
6. Digi2rd search. Another post from Thomas on word searches. The second word search on the USPC practice test (by Thomas, also can be seen in his post) is probably helpful here, since it trains you to look for words that have been mangled pretty significantly.
7. Sudoku. Not much needs to be said here. The USPC has had a nikoli Sudoku in the test in all the years from 2009 to 2012. Doing those will give you a good idea of what kind of constructions to look for. You’ll notice most of those are cleverly themed, so don’t come in expecting a vanilla puzzle here.
8. Tapa. This is a Serkan Tapa, so check the PDF for the Classic Tapa Contest that ran last year. 15 points means this one will probably sit a bit before the middle of the puzzles in that PDF, in terms of difficulty.
10. Number Tower. This one seems to be new. I’d be interested if anyone remembers any past spatial visualization puzzles in the USPC or other puzzle competitions. For now, doing a puzzle like Digitile from the 2010 USPC might help you get a bit more used to the shapes of the number bank. Although this puzzle will almost certainly fit the numbers in square boxes, instead of 3 by 5 rectangles.
11. Bombardoku. Those of you more familiar with Sudoku variations might know a good source of practice for this one. I will probably try to construct a preview myself.
12. Pathfinder. See Thomas’s notes on counting puzzles, although this one will probably be closer to a math puzzle. On that note, this math contest problem might make good practice. I suspect that problem is harder than what we’ll get on the USPC.
13. Looper. I know I’ve seen this one before, but I can’t find any examples of it. If you know of any, feel free to drop a comment. In the meantime I might throw one of these together, since it should be a quick one to construct.
14. Tight-fit Tom-Tom. This one is new. I would say to do Tight-fit Sudoku or some of Thomas Snyder’s Tom-Toms (I would certainly not recommend doing “Ken-kens”), but I have a feeling both will be misleading in some ways, as the fractions can change the game a lot. This is another one I’ll look into constructing.
15. Star Battle. We haven’t seen this type on the USPC before, despite how commonly it shows up on lots of other tests and WPCs. Thomas’s new blog has a nice sampling of very nicely constructed ones.
16. Kakuro Cards. Somewhat new, although the idea of a Kakuro variation on the USPC is not. Check Thomas’s post on Kakuro and variations first. I think this one is not as a big of a concern, and there’s three likely ways that the suits will change the game here:
a) Do good bookkeeping from start to finish.
b) Be on the look out for two sums which both want a particular number if you still have empty spaces of the same suit left in both sums. That’ll give you an either-or to work with. Bonus points if the sums cross.
c) If this isn’t enough, look for a group of high sums or a group of low sums that all use lots of copies of the same suit. You can only use those suits’ high and low numbers so many times.
17. Follow-Up. I know I’ve seen something like this before, but I don’t remember where. Anyways, either that example is awfully hard or this one is going to be tricky. Another one I’ll look into trying to make a preview of in advance.
18. Duello. I think this one is new. If you know any programming, you may want to do some brute forcing before the test for this one to see what rows and columns can possibly look like (without accounting for empty spaces).
19. Siamese Fences. They’ve broken it into two grids so that it can go black and white, but this is exactly the Colorlink type that I first posted forever ago. I’d encourage you to try some of those since there’s a lot of nonobvious tricks and patterns that come up in this type.
20. Thermo Skyscrapers. See Thomas Snyder’s blog for some Thermo Sudoku and Skyscrapers practice. These are two types that give the constructor a lot of freedom, so I’d recommend doing some from the same author to get a feel for what might happen on the test. The only puzzles I know that combine these are some inequality skyscrapers from WPCs, so I can’t post them. This is one that may be worth constructing in advance, albeit low priority since this much material already exists.
21. Ambiguity. This appeared in OAPC 8 under the name Rehber (edit: without the backwards/forwards choice. But I think those are still unique even with that rule). If you finish those and feel you need more practice, it may also be worth doing +-1 from OAPC 7, which similarly has you enter a word in an irregular fashion in every contiguous row and column of the grid. It’s kind of scary that they make this one the last puzzle on the test, since the type itself is not too difficult.
If you have any other sources of practice, or tips, or types you’ve constructed, feel free to comment.