Recent Posts

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Variant Theory / Re: Maths question: How many possible setups...?
« Last post by Asher Hurowitz on September 23, 2018, 10:56:57 pm »
This is an awesome question - working on it currently!  ;D
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Variant Theory / Maths question: How many possible setups...?
« Last post by ebinola on September 22, 2018, 06:35:09 pm »
Returning to chess variants, I've got an idea in the works that so far has posed a number of questions. One particular question requires some maths work that I can't wrap my head around, and I'm wondering if someone could help me.

The starting position for this game is identical to orthodox chess (pppppppp/rnbqkbnr...), but the player has some power over how their army is set up. The game has 5 piece classes (Pawn, Knight, Bishop, Rook, Queen), and 18 piece sub-classes (with their own unique properties). This makes for 90 unique pieces (excluding the King): 18 different Pawns, 18 different Knights, and so on. Multiples of pieces are allowed, i.e. you can have multiple Pawns of one sub-class. The King in this game has no special properties like the other pieces, it's just the same as any old King.

This setup phase is done blindly before the game begins, so neither player knows their opponent's setup until they see the starting position. Which leaves me with the question: how many possible setups exist with the above parameters?
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General Discussion / Leela vs. Stockfish9
« Last post by joejoyce on September 17, 2018, 10:49:03 am »
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General Discussion / Welcome Back! Questions
« Last post by Asher Hurowitz on September 11, 2018, 10:58:10 pm »
I'm excited for a new year!
How was your summer?
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General Discussion / Re: A New Channel + A ZERO PLAYER GAME?
« Last post by Asher Hurowitz on August 13, 2018, 04:04:50 pm »
Nice initiative , please follow up by making more videos.

Thanks! :D
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Twisty Puzzles / Re: My Twisty Puzzles + Speedcubing Channel
« Last post by Asher Hurowitz on August 13, 2018, 04:03:03 pm »
Awesome!
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Variant Theory / Kyoto Shogi: theoretical win for sente?
« Last post by HGMuller on July 30, 2018, 10:42:48 am »
Kyoto Shogi is a very peculiar chess variant, because the pieces change identity every time you move them. E.g. a Rook turns into a Pawn, and when the Pawn moves it turns again back into a Rook. Similarly a Gold General toggles to Knight, a Silver General to Bishop, and a Tokin (which also moves as Gold) to Lance. Only the King always remains itself. A weird property of the game is that pieces can get stuck (i.e. left without moves) when they advance too far, and that for some pieces this cannot be avoided: in Shogi a Knight always moves two ranks forward, and the Gold it morphs to then can at most move one rank back. A Tokin on last rank can stay alive arbitrarily may moves, but only if it moves back an forth (the latter as Lance) betwee two squares, which also isn't very useful.

For this reason the value of pieces is very much dependent on their location on the board. A Knight on the forelast rank (which has no moves) might even have negative value, as the enemy King can shelter behind it, and it would bind one of your other pieces to keep it protected against being taken by that King (which would give him the piece in hand).

I taught my engine CrazyWa (which was really designed to play Wa Shogi on an 11x11 board with 31 piece types) to play this game. I used hand-picked piece-value guestimates, so there is no guarantee its evaluation is very accurate. But when I use it to analyze the start position, it sees a big advantage for the sente player. When I analyze the positions to which the suggested moves lead, this advantage grows even more. This is indicative of a won position.

For CrazyWa the value of a piece in hand is slightly over 3. (It doesn't matter very much which piece; in hand they are about equally useful.) I could easily find lines of play for sente against any possible defense that would lead to a position that would analyze as above +6. Now I am working on demonstrating that from each of these positions an analysis score above +9 can be forced against any defense. Even if the scores given by CrazyWa are not very accurate, +9 must be way beyon the threashol for a certain win.
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Twisty Puzzles / My Twisty Puzzles + Speedcubing Channel
« Last post by abunickabhi on July 16, 2018, 03:42:56 am »
https://www.youtube.com/watch?v=nI6GksPoeOw
 
I have special interest in 5x5z5 order puzzle and its mods.
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General Discussion / Go Blindfolded
« Last post by abunickabhi on July 16, 2018, 03:40:14 am »
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