Author: Robert Hyatt
Date: 05:44:14 10/27/98
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On October 26, 1998 at 16:09:42, Robert Hyatt wrote: >On October 26, 1998 at 12:43:26, Bruce Moreland wrote: > >>Here is the tail end of a game played between my program (Ferret) on a 533 mhz >>Alpha and Crafty on a dual 450 mhz Pentium II, at time control of 5 0, on ICC. >> >>My program got smoked in a K+P ending it traded into (apparently) voluntarily. >> >>One of the things you hear about if you talk to old-timers in this field is that >>the square of the pawn is a totally important evaluation term. I'm not sure who >>said it, but someone said that it's worth 100 Elo points. This was a long time >>ago, back when programs would get killed in endings routinely, but I get the >>idea that this wisdom hasn't been re-evaluated much since then. It is my >>opinion that square of the pawn is worth almost nothing in practical play, since >>the number of K+P endings that actually occur, with play still in them, seems to >>be approximately zero. >> I am probably the "old-timer" that provided this "quote" I suspect. :) Context: Back in the very early 1970's, we (bert gower and myself) were entering "blitz" in USCF chess tournaments. We had several at the University where we were working (University of Southern Mississippi). Our official USCF rating was in the 1400's and stayed pretty constant for a couple of years. one common way we were losing was passed pawns that could out-run the king and promote (we were typically doing 4-5 plies back then, which was *not* enough to see a pawn running from h2 to h8. After watching yet another loss where we had won a pawn (or a piece for a couple of pawns or whatever) the humans would do their best to simplify into endings where they could trade away the last piece and be left with a pawn our king couldn't catch, even though we were "winning" when you counted material only. Finally I decided to stop this nonsense, and added the simple "square of the pawn" code to blitz (added it in 1972 if I recall correctly). Our USCF rating immediately went up from 1410 to 1550, with (effectively) no other changes of any kind. The funny thing was this code was *always* a part of the blitz/cray blitz program, yet I only recall one game where it made a difference in an ACM event. You can probably find the 1984 ACM event in Los Angeles where Cray Blitz was black against NuChess. We were really lost (down two pawns and cramped beyond repair) when NuChess had to choose between winning a center pawn and a passed pawn on the a-file. It chose the center pawn because it really wrecked our remaining pawn structure, but it also allowed us to trade off all pieces instantly. I was sick at the time, with a fever, and was taking some sort of medication that just about had me knocked out. For about 15 moves I had been looking at -2, -2, -2 evaluation. We had already clinched first place after 3 rounds, and if nuchess beat us they would have finished in clear 2nd. Mike was about to give the trophies out as it was about midnight or so and the spectators were tired also. Between moves, I happened to notice our terminal was saying +2, +2.5, +3, +4 etc.. I looked over to see what Gower had done, thinking he had entered the move wrong. After confirming our board matched the real board, my response was "holy shit, we are winning." That got Mike's attention and he came over to look. Sure enough, our a-pawn couldn't be stopped, and we won that game as well, that being the *only* computer-vs-computer game at an ACM event where this code made any difference. But one thing is for sure, back in 1972 the 100+ uscf rating improvement wasn't "guesswork" it was definitely "real"... all the games during that 1410-1560 improvement coming on the same xerox sigma 9 computer system...
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