Author: Martin Giepmans
Date: 18:23:56 03/10/02
Go up one level in this thread
On March 09, 2002 at 16:48:00, Albert Silver wrote:
>There is a friendly match between my club, the Tijuca Tenis Clube (the chess
>department) and the Clube De Xadrez Gunabara, over 8 boards. Both are among the
>most victorious and long-lasting clubs in Rio de Janeiro. The event comes with
>the blessing of the president of the Brazilian federation and will be worth some
>trophy they created that will be swapped back and forth over the next few years
>as I saw it had inscriptions for all winners until 2006 on it. There are two
>rounds at 90 min KO + 30 sec increment (though no increment today) played over
>this weekend, and I played 4th board. My game went well for me (especially
>considering how monstrously rusty I am) and I eventually arrived at the
>following position with about 5 minutes left.
>
>[D]6k1/4bp1p/2b3p1/2N1p3/1PP5/4N1P1/5P1P/6K1 w - - 0 1
>
>Obviously, many roads must lead to Rome here, but I saw a short winning sequence
>that made it clear and simple. The main line goes 1.b5! Bxb5 2.cxb5 Bxc5 3.Nd5
>f5 4.b6 Bd6 5.b7 Kf7 6.Nb4 Ke6 7.Nc6 and I win a piece and the game quite
>easily. The line is quite simple, and above all, with my knight fighting alone,
>there is little thinking to do after. I fed it to a few engines and was
>surprised to see how many fumbled around. Tiger found it in a few seconds but
>Junior 7 after about 6 minutes (and 22 half plies) gave me a line that had it
>win the piece in almost the same way in about 5 more moves. No idea why it
>preferred this. Fritz 7 also had a line that didn't seem like any great
>improvement and also preferred to take a bit longer. Obviously the issue must be
>one of evaluation, since they clearly don't think much of the knight fighting
>the pawns. This is a mistake as winning it after the line I gave above is a
>piece of cake AND it's quick. I say stray because the line they give is
>unconvincing usually.
>
>Here is Junior 7 (1.10/22) and its idea of an 'improved' final position: 1.Na6
>Bb7 2.Nd5 Bxa6 3.b5 Bxb5 4.cxb5 Bd6 5.b6 Kg7 6.Nc3 f5 7.Nb5 Bb8 8.f3 e4 9.fxe4
>fxe4 10.b7
>
>[D]1b6/1P4kp/6p1/1N6/4p3/6P1/7P/6K1 b - - 0 10
Yes, this is interesting.
b5 should be an easy win, but my engine prefers Na6 after a while.
(I don't know how much time you gave Tiger. It might also change it's mind)
In the last PV (depth 15) it even refuses to win a piece.
The issue is probably that the engine doesn't want to give up it's
two connected passed pawns.
SpiderChess (amd 1.2 GHz)
05 00:00:00 + 2.09 C5-A6 G8-F8 B4-B5 C6-F3 C4-C5
06 00:00:00 + 2.42 C5-A6 G8-F8 B4-B5 C6-F3 A6-C7 F7-F5
07 00:00:00 + 1.96 C5-A6 G8-F8 B4-B5 C6-B7 A6-B8 F7-F6 G1-F1
08 00:00:00 + 1.96 C5-A6 G8-F8 B4-B5 C6-B7 A6-B8 F7-F6 G1-F1 F8-E8
09 00:00:00 + 1.96 C5-A6 G8-F8 B4-B5 C6-F3 G1-F1 E7-G5 H2-H4 G5xE3 F2xE3
10 00:00:02 + 1.82 C5-A6 C6-F3 B4-B5 G8-F8 G1-F1 F7-F5 A6-C7 E7-D6 E3-D5
D6xC7 D5xC7
00:00:03 + 2.07 B4-B5 C6xB5 C4xB5 E7xC5 E3-C4 F7-F6 B5-B6 G8-F7 B6-B7
C5-A7 G1-G2 F7-E6 G2-F3
11 00:00:07 + 2.07 B4-B5 C6xB5 C4xB5 E7xC5 E3-C4 F7-F6 B5-B6 G8-F7 B6-B7
C5-A7 G1-G2 F7-E6 G2-F3 G6-G5
12 00:00:14 + 2.04 B4-B5 C6xB5 C4xB5 E7xC5 E3-C4 F7-F6 B5-B6 C5xB6 C4xB6
G8-F7 G1-G2 F6-F5 G2-F3 E5-E4 F3-E3 F7-E6
13 00:00:40 + 1.92 B4-B5 C6xB5 C4xB5 E7xC5 E3-D5 F7-F5 B5-B6 C5xB6 D5xB6
G8-F7 G1-G2 E5-E4 B6-D7 F7-E7 D7-E5 E7-D6 E5-F7 D6-D5
14 00:01:40 + 1.93 B4-B5 C6xB5 C4xB5 E7xC5 E3-D5 F7-F5 B5-B6 C5-D6 B6-B7
G8-F7 G1-F1 F7-E6 D5-B6 E5-E4 F1-E2 D6-E5 E2-E3
00:02:43 + 1.98 C5-A6 C6-B7 B4-B5 G8-F8 A6-C7 B7-F3 E3-D5 E7-D6 B5-B6
F7-F5 C4-C5 D6xC5 C7-E6 F8-G8 E6xC5 F3xD5
15 00:04:44 + 1.90 C5-A6 C6-B7 B4-B5 G8-F8 A6-C7 E7-D6 C7-D5 F7-F5 D5-F6
F8-E7 F6xH7 D6-C5 H7-G5 C5-D4 H2-H4
Martin
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.