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Subject: Re: Chesslab and Novag Opal get this wrong: Does your program get it right?

Author: Francis Monkman

Date: 17:02:43 05/01/99

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On May 01, 1999 at 19:44:01, Michael de la Maza wrote:

>I was playing white against my portable Novag Opal and arrived at this position:
>
>White: Qa7, Re1, Kg1, and pawns on h2, g2, f2, and e3
>Black: Qb5, Nc4, Rd3, Kg8, and pawns on e4, f5, g5, and h7
>White to move
>
>This is clearly a won game for black, but to my amazement I was a able to draw
>by three-fold repetition (1. Qe7 h6 2. Qe6+ Kg7 3. Qe7+ Kg6 4. Qe6+ Kg7 etc.)
>
>I figured that Opal was just such a weak computer that it didn't see the many
>black moves that preserve the win and instead settled for a draw because it
>didn't want to lose a pawn or two.
>
>So I checked with ChessLab (www.chesslab.com) and, amazingly, the best variation
>that it gives is actually a win for WHITE!  Here it is:
>1. Qe7  h6
>2. Qe6+ Kg7
>3. Qe7+ Kg6
>4. Qe6+ Kh5
>5. Qf7+ Kh4
>6. g3+  Kg4
>7. h3+  Kf3
>8. Qh5+ g4
>9. hxg4
>and mate in two for WHITE
>
>Two things stand out about this line: 1) There are several ways for black to win
>but neither program found any good line for black and 2) The variation that
>leads to mate for white seems so trivial that any program should be able to
>avoid it.
>
>I'm curious to know how easy other programs find this position.
>
>
>The settings for the two programs were as follows:
>Novag Opal: "Average of 120 seconds per move"
>Chesslab: "Long Analysis"
>
>Michael

Genius4 (P Pro200) finds the following line, almost immediately:

1 Qe7 Qe5
2 Qxe5 Nxe5
3 Rb1 Kf7
4 g3 h5
5 Rb7+ Ke6
6 Rb6+ Rd6
7 Rxd6+ Kxd6
8 Kg2 Nf3

Which makes a pretty picture!

FM



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