Author: Robert Hyatt
Date: 08:11:08 01/18/98
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On January 17, 1998 at 23:39:02, Bruce Moreland wrote: > >On January 17, 1998 at 18:29:35, Robert Hyatt wrote: > >>Some of the Bratko-Kopec positions were like this, but there were a few >>that I disagreed with, Kmoch be damned. :) But they were nice in that >>deeper searches wouldn't help if you didn't understand the particular >>pawn structure nuance they were targeting... > >The problem I had with some of the BK problems wasn't that the problems >had incorrect solutions, but rather that programs would find answers for >superficial reasons. For instance, position 4, which is from Spielmann >vs Walter, 1928: > >rnbqkb1r/p3pppp/1p6/2ppP3/3N4/2P5/PPP1QPPP/R1B1KB1R w KQkq - 0 1 > >The key is 1. e6, is meant to be a sacrifice. The reply 1. ... fxe6 is >crushed by 2. Qh5+, but there is nothing in the test that ensures that >programs understand the consequences of 1. ... fxe6. > >I bet many of the programs tested by BK over the years would not have >played 2. Qh5+. Here is this position: > >rnbqkb1r/p3p1pp/1p2p3/2pp4/3N4/2P5/PPP1QPPP/R1B1KB1R w KQkq - 0 2 > >How long does it take your favorite program to find 2. Qh5+ here? about 45 seconds on the P6... but the score goes from .24 for Nex6 to .25 for Qh5+... :) at depth=11 Qh5 fails high. So 13 plies from the original position... to get a *real* result and not a positional one... the score after 11 plies is +1.6 fail hi takes about a minute. It also fails high again at depth=11... > >Imagine how far beyond *any* micro this was in 1980 or so, but there >they all are, getting full credit for this problem, they all found 1. >e6. > >My favorite BK problem is #22: > >2r2rk1/1bqnbpp1/1p1ppn1p/pP6/N1P1P3/P2B1N1P/1B2QPP1/R2R2K1 b - - 0 1 > >The key is 1. ... Bxe4. This was a very good recapture extension >problem in its day, but now you'll probably find it in a second or two. > >bruce
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