Author: Dann Corbit
Date: 16:48:17 05/12/00
Go up one level in this thread
On May 12, 2000 at 18:51:23, Ed Schröder wrote: >On May 12, 2000 at 16:21:01, blass uri wrote: >>[D]1r3nk1/3rb1p1/p2p1pP1/1p2p3/Pnq1P1R1/2N1B3/1PPR3P/2NQ3K w - - 0 1 >> >>This position is from the ssdf games(Junior5-Junior6). >>The evaluation was close to equality and suddenly Junior5 failed high and found >>more than 1 pawn advantage for white. >> >>I post this position to demonstrate the fact that tactics is not only >>sacrifices. >> >>Unfortunately tactical test positions are usually sacrifices. >> >>I am also not sure if there is only one good move for white. >>White played in the game Rg2. >>This is a good move with the idea to give mate by Rh4 and Qh5 but I am not sure >>if this is the only good move and it is possible that axb5 and after it Rg2 also >>give the same result(I did not check it) >> >>The point is not to find Rg2 but to find a significant change in the evaluation. >> >>How much do programs need to fail high? >> >>I think it is a good idea to generate a tactical test suite based on positions >>from practical games and not based on finding sacrifices. >> >>In order to do it we need to analyze many games and find cases when there is a >>significant change in the evaluation. >> >> >>Uri > >The latest Rebel running under EPD2DIAG: > >00:01 07.00 0.44 1.axb5 axb5 2.Nd5 Nxd5 3.exd5 Qc7 4.Qf1 Bd8 5.Qh3 >00:03 08.00 0.37 1.axb5 axb5 2.Nd3 Ra8 3.Nxb4 Qxb4 4.Qc1 Qc4 5.Nd5 Ra2 >00:11 09.00 0.44 1.axb5 axb5 2.Nd3 Ra8 3.Rf2 Nc6 4.Nd5 Qa2 >00:23 09.15 0.44 1.Rdg2 >00:28 09.15 0.75 1.Rdg2 d5 2.exd5 Nxd5 3.Rxc4 Nxe3 4.Qf3 Nxc4 5.axb5 axb5 >6.Nd3 >00:47 10.00 0.80 1.Rdg2 d5 2.exd5 Qc7 3.axb5 axb5 4.Rh4 f5 5.Rh5 Bc5 6.Bxc5 >Qxc5 >01:23 11.00 0.68 1.Rdg2 d5 2.exd5 Qc8 >01:37 11.01 0.80 1.axb5 axb5 2.Rdg2 d5 3.exd5 Qc7 4.Rh4 f5 5.Rh5 Bc5 6.Bxc5 >02:06 12.00 0.84 1.axb5 axb5 2.Rdg2 d5 3.exd5 Nxd5 4.Rxc4 Nxe3 5.Qxd7 Nxd7 >6.Rc7 Nxg2 7.Rxd7 b4 8.Rxe7 bxc3 >03:54 13.00 0.89 1.axb5 axb5 2.Rdg2 d5 3.Rh4 f5 4.Rh3 Rd6 5.exf5 Rf6 >04:35 13.01 0.98 1.Rdg2 d5 2.exd5 Qc8 3.Qf3 Qd8 4.axb5 Nxd5 5.Nxd5 Rxd5 6.b6 Absolutely incredible! Amy finds it after 25 minutes, but (for all intents and purposes) hangs in the research: GamePhase: Opening It Time Score principal Variation 7 1.2 -0.144 1. Nd5 Nxd5 2. exd5 Qc7 3. axb5 axb5 4. Qe2 Rdd8 7 1.4 +++ 1. axb5 7 1.5 -0.032 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Nd5 Qxb2 7 2.3 -0.032 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Nd5 Qxb2 8 3.3 -0.016 1. axb5 axb5 2. Nd5 Nxd5 3. exd5 Qc7 4. Kg1 Ra8 5. Nd3 8 5.5 -0.016 1. axb5 axb5 2. Nd5 Nxd5 3. exd5 Qc7 4. Kg1 Ra8 5. Nd3 9 9.6 -0.080 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Rf2 d5 5. exd5 Qxb2 9 15.6 -0.080 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Rf2 d5 5. exd5 Qxb2 10 23.9 +0.112 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Rf2 Qc4 5. Nd5 Qc6 6. Kg1 10 31.5 +0.112 1. axb5 axb5 2. Nd3 Ra8 3. Nxb4 Qxb4 4. Rf2 Qc4 5. Nd5 Qc6 6. Kg1 11 1:00 +0.064 1. axb5 axb5 2. Nd3 Nxd3 3. Rxd3 Qc8 4. Kg1 Qe8 5. Rd2 b4 6. Nd5 Nxg6 11 1:22 +0.064 1. axb5 axb5 2. Nd3 Nxd3 3. Rxd3 Qc8 4. Kg1 Qe8 5. Rd2 b4 6. Nd5 Nxg6 12 2:39 +0.192 1. axb5 axb5 2. Nd3 Nxd3 3. Rxd3 Qc8 4. Nd5 Qe8 5. Rg1 Rbd8 6. Nb6 Ra7 7. Nd5 12 3:22 +0.192 1. axb5 axb5 2. Nd3 Nxd3 3. Rxd3 Qc8 4. Nd5 Qe8 5. Rg1 Rbd8 6. Nb6 Ra7 7. Nd5 13 6:17 +0.144 1. axb5 axb5 2. Nd3 Nxd3 3. cxd3 Qe6 4. Rg1 Bd8 5. Rdg2 Rc7 6. Nd5 Rc6 7. Rc2 Rbc8 13 8:13 +0.144 1. axb5 axb5 2. Nd3 Nxd3 3. cxd3 Qe6 4. Rg1 Bd8 5. Rdg2 Rc7 6. Nd5 Rc6 7. Rc2 Rbc8 14 16:42 +0.176 1. axb5 axb5 2. Nd3 Nxd3 3. Rxd3 Qc8 14 87:07 +++ 1. Rdg2 Like the energizer bunny, it keeps going and going and going... Which brings up a point... I have seen some chess engines do something silly. The have finished a ply (say, for instance, ply 14 side to move) and do a fail high. Then *instead* of choosing the move that failed high, they stick with the one that was completed!!! {in this case, the engine might still play axb5 -- though I doubt that Amy has this fault}. Why would anyone want to do that? It does not make any sense to me.
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