Author: Uri Blass
Date: 12:06:40 09/17/04
Go up one level in this thread
On September 17, 2004 at 14:21:16, Dann Corbit wrote: >On September 17, 2004 at 11:42:38, Robert Hyatt wrote: > >>On September 16, 2004 at 19:48:59, Dann Corbit wrote: >> >>>On September 16, 2004 at 18:18:13, Robert Hyatt wrote: >>> >>>>On September 16, 2004 at 12:52:43, Dann Corbit wrote: >>>> >>>>>On September 16, 2004 at 07:37:01, Ricardo Gibert wrote: >>>>> >>>>>>Your post is a good example of what happens when one jumps to a conclusion >>>>>>without taking the minimum amount of effort needed to understand what is really >>>>>>going on. >>>>> >>>>>I disagree completely, also with everyone else. >>>> >>>>Taking a _longer_ path to win is counter to a tactical test idea. Clearly the >>>>move given is bad, because it just extends the game and reaches the same >>>>position a second time where the _real_ solution has to be played. That is >>>>pointless... >>>> >>>>Otherwise a mate in 3 might turn into a mate in 40 if one side takes every >>>>opportunity to first repeat a second time before making progress... >>> >>>The pv shown by Arasan leads to a win. >>>If it lead to a draw or some other problem I would agree. >> >>You ask a student to add 2 + 2. >> >>He turns in the following: >> >> >>sqrt(100) / sqrt(25) + log10(100) and solves that and turns it in with his >>scratch paper. Do you give him credit? I do not. There are a zillion longer >>ways to do something, such as a tree search in chess. Tactical solutions are >>about the shortest way to win. IE if there is a mate in 8 and a mate in 10, the >>correct answer is the mate in 8. > >There are often strange solutions to test problems (e.g. tossing a queen due to >tablebase simplification). If a chosen move wins 100% of the time, and the >program sees a clear solution, it is a winning move. A winning move cannot be >said to be incorrect. It has exactly the same value as a winning move to a >shorter solution. > >>If there are two equal ways to win, then yes, >>either is correct. But to intentionally repeat a position makes no sense and I >>give it a "zero" as it is pointless... >> >>If you want to count it right, that's ok, but I disagree and I won't. Otherwise >>each WAC position probably has _multiple_ correct solutions... > >If a problem is not proven all the way to win/loss/draw then it is really open. >If there are 10 moves that lead to a definite win, then all ten moves are >solution moves. Including crazy moves like tossing a queen for a tablebase >simplification. I disagree. There are cases when there is only one solution that you can expect chess programs without bugs to find and it is the right solution(tablebase win is not a bug in chess programs so it can be included as a solution but a win by repetition of the root position certainly incdicates a bug). WAC is used to test chess programs for not having bugs in the search and failure should suggest a bug. If you include the stupid move of arasan as a solution then the wac test is losing it's value to detect bugs. By your definition a lot of problems in WAC have more than one solution I found 7 position with more than one solution in the first 20 positions simply by using Fritz at 2 best move in 6 cases or by using my brain in one case to see that white can force repetition and win later. 2rr3k/pp3pp1/1nnqbN1p/3pN3/2pP4/2P3Q1/PPB4P/R4RK1 w - - bm Qg6; id "WAC.001"; 1)Nh5 also wins and not only Qg6 r1bq2rk/pp3pbp/2p1p1pQ/7P/3P4/2PB1N2/PP3PPR/2KR4 w - - bm Qxh7+; id "WAC.004"; 2)Qe3 also wins r4q1k/p2bR1rp/2p2Q1N/5p2/5p2/2P5/PP3PPP/R5K1 w - - bm Rf7; id "WAC.008"; 3)Nf7+ Kg8 Nh6+ Kh8 Rf7 also wins r2rb1k1/pp1q1p1p/2n1p1p1/2bp4/5P2/PP1BPR1Q/1BPN2PP/R5K1 w - - bm Qxh7+; id "WAC.014"; 4)Ne4 also wins 1R6/1brk2p1/4p2p/p1P1Pp2/P7/6P1/1P4P1/2R3K1 w - - bm Rxb7; id "WAC.015" 5)b4 also wins 1k5r/pppbn1pp/4q1r1/1P3p2/2NPp3/1QP5/P4PPP/R1B1R1K1 w - - bm Ne5; id "WAC.017"; 6)I suspect that b6 also wins. r2qkb1r/1ppb1ppp/p7/4p3/P1Q1P3/2P5/5PPP/R1B2KNR b kq - bm Bb5; id "WAC.020"; 7)Be6 also wins Uri
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