Author: Robert Hyatt
Date: 11:18:13 03/01/01
Go up one level in this thread
On March 01, 2001 at 08:21:38, Sune Larsson wrote: >On February 28, 2001 at 23:19:12, Robert Hyatt wrote: > >>On February 28, 2001 at 13:48:00, Sune Larsson wrote: >> >>>On February 28, 2001 at 13:00:53, Robert Hyatt wrote: >>> >>>>On February 28, 2001 at 11:12:09, Sune Larsson wrote: >>>> >>>>> >>>>> [D]4n3/1b3k1p/p2p2p1/3Pp3/2P3P1/6PP/2BB4/6K1 w - - 0 1 >>>>> >>>>> This is Hort-Ciocaltea, Budapest 1973. Only two moves are required >>>>> to immobilize the black knight and pave the way for the victorious >>>>> march of the white king to the deserted queenside: >>>>> >>>>> 1.g5! Bc8 2.g4! and black's position is ripe for resignation. >>>>> >>>>> Test: The above move order should be rewarded with big +scores for white. >>>>> >>>>> Sune >>>> >>>> >>>>There may be more than one winning plan here. Crafty thinks that Ba5 wins a >>>>pawn, for example... eval = +1.26 after 18 plies, almost 2 minutes: >>>> >>>> 17 1:01 0.99 1. Ba5 Ke7 2. Kf2 Bc8 3. Kf3 Bd7 4. >>>> Ke4 Kf6 5. Bb4 Nb6 6. Bd3 Nc8 7. c5 >>>> dxc5 8. Bxc5 a5 9. d6 >>>> 17-> 1:09 0.99 1. Ba5 Ke7 2. Kf2 Bc8 3. Kf3 Bd7 4. >>>> Ke4 Kf6 5. Bb4 Nb6 6. Bd3 Nc8 7. c5 >>>> dxc5 8. Bxc5 a5 9. d6 >>>> 18 1:40 1.26 1. Ba5 Ke7 2. Kf2 Bc8 3. Kf3 Bd7 4. >>>> Ke4 Kf6 5. Bb3 h5 6. Bb4 hxg4 7. hxg4 >>>> Ke7 8. c5 dxc5 9. Bxc5+ Kf6 10. g5+ >>>> Kxg5 11. Kxe5 >>>> 18-> 1:53 1.26 1. Ba5 Ke7 2. Kf2 Bc8 3. Kf3 Bd7 4. >>>> Ke4 Kf6 5. Bb3 h5 6. Bb4 hxg4 7. hxg4 >>>> Ke7 8. c5 dxc5 9. Bxc5+ Kf6 10. g5+ >>>> Kxg5 11. Kxe5 >>> >>> Interesting line. Can Crafty win the above position after 11.-Kg4? >>> >>> Sune >> >> >>Good question. A brief note about chess programs. When they produce a PV >>as above, the first move is the one they play. The second move is the one >>they expect, but it is less accurate as it is the result of a search that is >>one ply shallower than the search to choose the _first_ move. By the time >>you reach the end of the PV, it is _highly_ likely that those moves will never >>be played in a real game. The last move is based on a 1 ply search, for >>example, and no one would consider that to be reasonable chess... >> >> >>IE when a GM gives me a variation to look at, _every_ move generally is >>a sound move. When a computer gives me a variation, the deeper the move >>in the variation, the less likely it is to be the best move. > > Okey, from your statement I conclude that we cannot trust the Crafty line > above. Furthermore it doesn't even come close to GM Hort's choice or > the theme of immobilizing the black knight with 1.g5! and 2.g4! > > Sune Here is a quote from a very good GM on ICC (Not Roman this time). "I notice that when crafty is whispering analysis, the first move or two are _always_ very strong. But the further down in the PV you go, the less sense the moves make at times. why is this?" It is based on the reasoning I gave... I rarely fault the move the thing produces, as the moves are good enough to give human GM players fits. But I am _certain_ that if Crafty had to play the entire PV in a game, it would end up in much difficulty... most of the time..
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.