Author: Pete R.
Date: 17:17:28 06/02/00
Go up one level in this thread
On June 02, 2000 at 19:45:18, Pete R. wrote: >On June 02, 2000 at 18:04:48, Ed Schröder wrote: > >>On June 02, 2000 at 16:31:12, Pete R. wrote: >> >>>On June 02, 2000 at 08:32:31, blass uri wrote: >>> >>>>This position is from the game tal2.03-Junior6a >>>> >>>>[D]r2qr3/pb3pk1/np3b1N/2pp3Q/3P4/1PR1P1P1/P4PBP/5RK1 w - - 0 1 >>>> >>>>1)How much time does your program need to find 1.g4? >>>> >>>>2)How much time does your program need to avoid 1.g4? >>>> >>>>1.g4 is probably not the best move because of the line 1.g4 Rh8 2.Qxf7+ Kxh6 >>>>3.f4 Rg8 4.Qxb7 Nb4 5.g5+ Bxg5 6.fxg5+ Qxg5 7.Rf2 Raf8 8.Qd7 Rxf2 >>>> >>>>Uri >>> >>>I have not analyzed the lines myself to determine the best move, but here is the >>>output from Fritz 5.32, followed by my comments: >>> >>>New position >>>r2qr3/pb3pk1/np3b1N/2pp3Q/3P4/1PR1P1P1/P4PBP/5RK1 w - - 0 1 >>> >>>Analysis by Fritz 5.32: >>> >>>-+ (-2.94) 1.dxc5 Bxc3 2.Nxf7 00:00:00 >>>= (-0.25) 1.Nxf7 00:00:00 >>>² (0.31) 1.Nxf7 00:00:00 >>>= (0.25) 1.Nxf7 Qe7 00:00:00 >>>³ (-0.47) 1.Nxf7 Qe7 2.Ne5 00:00:00 >>>³ (-0.44) 1.Rfc1 00:00:00 >>>³ (-0.41) 1.Rfc1 Qd7 2.Nf5+ Kg8 00:00:00 >>>³ (-0.37) 1.Rd3 00:00:00 >>>³ (-0.34) 1.Rd3 Qd7 2.dxc5 Nxc5 3.Nf5+ Kg8 00:00:00 >>>³ (-0.31) 1.Qxf7+ 00:00:00 >>>² (0.50) 1.Qxf7+ Kxh6 2.Qxb7 Nb4 00:00:00 >>>= (0.06) 1.Qxf7+ Kxh6 2.Qxb7 Nb4 3.a3 00:00:00 >>>= (0.09) 1.Nxf7 00:00:00 >>>² (0.44) 1.Nxf7 Qd7 2.Ne5 Bxe5 00:00:00 >>>² (0.53) 1.Nxf7 Qe7 2.Nh6 Rh8 3.Nf5+ Kf8 00:00:00 >>>² (0.56) 1.Nxf7 Qd7 2.Nh6 Kf8 3.Nf5 Rac8 00:00:00 >>>² (0.47) 1.Nxf7 Qe7 2.Nh6 Bc8 3.Qxd5 Nc7 4.Nf5+ Bxf5 5.Qxf5 cxd4 00:00:00 >>>² (0.69) 1.Nxf7 Qc7 2.Nh6 Rf8 3.Nf5+ Kg8 4.f4 Rae8 5.Nh6+ Kg7 00:00:03 >>>± (0.75) 1.Nxf7 Qc7 2.Nh6 Rh8 3.Nf5+ Kf8 4.Qg6 Bg7 5.Rd1 Rd8 00:00:08 >>>² (0.69) 1.Nxf7 Qc7 2.Nh6 Rad8 3.Nf5+ Kf8 4.a3 Qf7 5.Qxf7+ Kxf7 00:00:25 >>>± (0.81) 1.Nxf7 Qc7 2.Nh6 Rh8 3.Nf5+ Kf8 4.Qg6 Bg7 5.Bxd5 Bxd5 00:01:28 >>>± (0.81) 1.Nxf7 Qc7 2.Nh6 Rf8 3.g4 Kh8 4.Nf7+ Kg8 5.Qg6+ Bg7 00:03:50 >>>± (0.84) 1.g4 00:28:15 >>>± (1.06) 1.g4 Rh8 2.Qxf7+ Kxh6 3.f4 Rg8 4.g5+ Bxg5 5.Qxb7 Nc7 01:22:35 >>>± (1.00) 1.g4 Rh8 2.Qxf7+ Kxh6 3.f4 Rg8 4.Qxb7 Nc7 5.h3 Bg7 01:41:27 >>> >>>The ply depths are not recorded, but Fritz switched to g4 at about 12/37. It >>>stuck a long time at this depth, as you can see this took 28:15 on a PII 400 >>>with 128MB. I ended the analysis at depth 14/44 or some such, but if g4 is not >>>best it would take at least an overnight search to get deep enough. >> >>It's indeed a tricky position. Mine finds g4 on ply 11 score +0.80 (or so) >>then sticks to g4 on ply12 and 13 whith a dropping score and then on ply >>14 finally back to original which was Nxf7 (score about 0.40). I lost the >>analysis, sorry. >> >>Ed > >Hiarcs switches to 1.g4 after a minute or so, but after doing some guided >analysis I think most engines will reject 1.g4 eventually. Not that it is so >bad, I think it leads to an easy draw. Nxf7 seems slightly better in that white >can make some threats advancing kingside pawns. But so far as I could see black >has enough to defend, so that from here no computer is going to find a >dramatically best move. It would take a good human player to find a good plan >here and get a win for white, someone much better than I am. ;) Having studied it a bit further, I would say that this type of position is too much for computers in the sense that a human can look at the pawn skeleton and come up with a plan based on that, but a computer will never see it. While the 1.g4 line probably draws, I think white can get good chances in the 1. Nxf7 lines by trying to trade queens and then pressing his connected passers. But how do you program something like that? If good pawn skeleton then trade off pieces, of course, how easy. ;) Perhaps some programs have this sort of heuristic, i.e. promote the tendency to trade pieces if the pawn structure looks favorable for trading down? Anyway this is a very difficult position for computers to make sense of, so I think strong humans will have very good chances with white here because of the pawn structure.
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