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This item is a game information page
It belongs to categories: Orthodox chess, 
It was last modified on: 2010-01-10
 By Joe  Joyce. Great Shatranj. Great Shatranj. (10x8, Cells: 80) [All Comments] [Add Comment or Rating]
H.G.Muller wrote on 2008-04-24 UTC
Indeed, my method is very time consuming. But I am still developing it, and hope to make it more efficient. (For instance, I have not really established what the optimal time control is to play these games. I am using 40/2' with fairy-Max now, and 4/1' for my better engine Joker, but it turns out that Joker finds the same Pawn-odds score at 40/10' as at 40/2'. If that would be true for all scores, I could speed the process up by a factor 6!) I currently have one dual-core PC entirely dedicated to Chess testing (running 24/7). And I consider fairy-piece values one of the spear points of my research. I have too many spear points, though: I develop two Chess engines, micro-Max and Joker, also in variant versions, am currently the main contributor to the WinBoard open-source GUI (and in particular the only one that cares about variant support). I want to write a Shogi engine, and develop a much faster end-game-tablebase builder. I could use an extra computer, but I want to postpone my next buy until I can get an 8-core Nehalem. Because I want to develop a new SMP algorithm for tree search that scales better on large numbers of cores, and I really needs a machine to test this on. So for the time being, I will have to do with my 2.4GHz Core 2 Duo. But eventually I will do most fairy pieces. I will probably convert Joker to handle fairy pieces as well, as it can reach the same quality play in a fraction of the time. If you have a computer (which is likely, since you post here), you could easily do such tests yourself too, however. It is harder on the PC than on the tester! It is just a matter of letting it run, and once a day look at the result, set up a new position and start a run for that. I am currently running a test with 2 Ministers against 2 High Priests (starting at the A and C positions of Capablanca Chess, so in a context of all normal Chess pieces). This seems a pretty even battle, In fact, after 62 games, the High Priests are even leading (26+ 22- 14=, 53.2%). I guess I will let it run overnight. But they are very close, so the High priestess is also more a Rook replacement than a Bishop replacement. My Rook opening value on 10x8 is only 475. So 625 is even on the strong side for a Rook. (Why do you find that surprising? A Rook on 10x8 has a MAXIMUM of 16 moves, and most will be blocked on a non-empty board. All 16 moves of Minister and High-Priest are unblockable.) I have not tried your leaper replacements for Bishop and Rook yet, but some time ago I very precisely tested a similar piece, F+D, because I wanted it to investigate pair bonuses for color-bound pieces (and F+D is color-bound). A pair of these pieces tested nearly as strong as a pair of Knights, perhaps a quarter Pawn weaker (this was on 8x8, though). This would make it 290, as my Knight is 300 on 10x8. I don't know yet, however, how much of this is pair bonus. But if a color-bound piece with 8 unblockable moves can be wrth as much as a Knight (at least, in a pair), the non-colorbound pieces F+A and D+W must be similar or better, and thus good Knight replacements. It is funny that a pair of the F+D, which is the (color-bound) conjugate of the King, is worth nearly a Knight (when paired), while a non-royal King is worth significantly less than a Knight (nearly half a Pawn less). But of course a Ferz is also worth more than a Wazir, zo maybe this is to be expected.