Author: Jarkko Pesonen
Date: 23:45:24 04/29/02
Go up one level in this thread
On April 29, 2002 at 15:46:36, Robert Hyatt wrote:
>On April 29, 2002 at 15:06:54, Miguel A. Ballicora wrote:
>
>>I guess that Bc3 played by CT is partially because CT has code that detects
>>a trapped queen. So, after Bc3 Qxb6 CT thinks that the queen is in bad shape
>>so it is worth losing a doubled pawn. Some time ago CT was very succesful in a
>>position that few commercial programs (including Fritz) detected as bad, when a
>>queen was trapped. I guess that this code backfired here, in combination with a
>>horizon effect in which it did not see that Bc3 did not really threat the rook
>>at a1.
>>
>>My program gaviota has some code to detect a trapped queen and wants to play Bc3
>>for while up to ply 10 when it changes to Bc5. Interestingly, Gaviota did well
>>in that position that CT did well. I am not trying to compare my weak amateur
>>program with tiger, I am just trying to make a correlation.
>>
>>I guess that this code could have created a problem in this particular position.
>>
>>Did I guess right Christophe?
>>
>>Regards,
>>Miguel
>
>
>I ran this on Crafty and got the following:
>
> 8-> 0.23 -1.38 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Kg8
> 4. Rc2 Rxa4 5. Nd2
> 9 0.34 ++ 1. ... Bc3!!
> 9 0.75 -1.95 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Bf1 R4a5 5. Rc2 Rb8 6. Rbc1 Bxb5
> 9-> 0.82 -1.95 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Bf1 R4a5 5. Rc2 Rb8 6. Rbc1 Bxb5
> 10 0.98 -2.18 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Bf1 R4a5 5. Be2 Bxb5 6. Bf1 Rb8
> 7. Rc2 <HT>
> (3) 10-> 1.41 -2.18 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Bf1 R4a5 5. Be2 Bxb5 6. Bf1 Rb8
> 7. Rc2 <HT>
> (2) 11 2.33 -2.21 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Ra2 6. Kg1 R8a5
> 7. Rbc1 Bxb5
> (2) 11-> 4.04 -2.21 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Ra2 6. Kg1 R8a5
> 7. Rbc1 Bxb5
> 12 5.90 -2.27 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Kh2 R4a5 5. Ng1 Bxb5 6. Rb3 Bxd3
> 7. Rxb6 Bc4 8. Rxb7
> 12-> 6.75 -2.27 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Kh2 R4a5 5. Ng1 Bxb5 6. Rb3 Bxd3
> 7. Rxb6 Bc4 8. Rxb7
> 13 11.26 -2.34 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Ra2 6. Kg1 R8a5
> 7. Rbc1 Kg8 <HT>
> 13-> 13.27 -2.34 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Ra2 6. Kg1 R8a5
> 7. Rbc1 Kg8 <HT>
> 14 21.58 -2.35 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Rxb5 6. Bh3 Bc6
> 7. Kg2 Ke7 8. Rbc1 Rc5
> 14-> 25.41 -2.35 1. ... Bc3 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Rd1 R4a5 5. Kh2 Rxb5 6. Bh3 Bc6
> 7. Kg2 Ke7 8. Rbc1 Rc5
> 15 1:28 -2.04 1. ... Bc3 2. Qxb6 Qe7 3. Nh4 Kg8 4.
> Bf3 Bb3 5. Bg4 Bf7 6. Bd1 Bxa1 7. Rxa1
> R5a7 8. Nf3 <HT>
> 15-> 2:06 -2.04 1. ... Bc3 2. Qxb6 Qe7 3. Nh4 Kg8 4.
> Bf3 Bb3 5. Bg4 Bf7 6. Bd1 Bxa1 7. Rxa1
> R5a7 8. Nf3 <HT>
> 16 5:44 -2.12 1. ... Bc3 2. Qxb6 Qe7 3. Nh4 Kf7 4.
> f4 Bxa1 5. Rc7 Bd7 6. Bh3 Bxh3 7. Rxe7+
> Kxe7 8. Qc7+ Bd7 9. fxe5 fxe5 10. Qxe5+
> Kd8 11. Qh8+ Kc7 12. Qxh7 Rxa4 13.
> Nxg6
> 16-> 6:11 -2.12 1. ... Bc3 2. Qxb6 Qe7 3. Nh4 Kf7 4.
> f4 Bxa1 5. Rc7 Bd7 6. Bh3 Bxh3 7. Rxe7+
> Kxe7 8. Qc7+ Bd7 9. fxe5 fxe5 10. Qxe5+
> Kd8 11. Qh8+ Kc7 12. Qxh7 Rxa4 13.
> Nxg6
> 17 11:57 -1.93 1. ... Bc3 2. Qxb6 Qe7 3. Nh4 Kf7 4.
> f4 exf4 5. gxf4 Bxa1 6. Rc7 Bd7 7.
> e5 fxe5 8. Nf3 Kg8 9. Nxe5 Qe6 10.
> Nxd7
> 17 20:16 -2.06 1. ... Bc5 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Nd2 Ra3 5. Nb3 Bd6 6. Bf1 Kf7 7.
> Nd2 Rc3 8. Nc4 Bf8 9. f4 Bxh6 10. Nxb6
> Rxc1 11. Rxc1
> (3) 17-> 20:21 -2.06 1. ... Bc5 2. Qxd7 Bxd7 3. Rab1 Rxa4
> 4. Nd2 Ra3 5. Nb3 Bd6 6. Bf1 Kf7 7.
> Nd2 Rc3 8. Nc4 Bf8 9. f4 Bxh6 10. Nxb6
> Rxc1 11. Rxc1
>
>
>So for my code, thru depth 17, Bc3 and Bc5 are very close. Only after a
>monstrous search does Bc5 look .1 better...
>
>If a program plays Bc5 over Bc3 it probably is not due to tactics, but due
>to some eval term instead...
[d]r4k2/1pQq3p/1p2bppP/rP2p3/Pb1pP3/3P1NP1/5PB1/R1R3K1 b - - 0 1
Are you sure?
My little tweaked crafty 18.12 gives
11 30.99 -1.94 1. ... Bc3 2. Qxb6 Bxa1 3. Rc7 Qd8
4. Qc5+ Kg8 5. Rg7+ Kh8 6. Ng5 Bg8
7. Rxh7+ Bxh7 8. Nf7+ <HT>
11 47.16 -2.16 1. ... Bc5 2. Rxc5 bxc5 3. Qxc5+ Kg8
4. Qa3 Kf7 5. Qc1 Rxa4 6. Rxa4 Rxa4
7. b6 Ra2
11-> 52.52 -2.16 1. ... Bc5 2. Rxc5 bxc5 3. Qxc5+ Kg8
4. Qa3 Kf7 5. Qc1 Rxa4 6. Rxa4 Rxa4
7. b6 Ra2
12 1:18 -2.16 1. ... Bc5 2. Rxc5 bxc5 3. Qxc5+ Kf7
4. Rc1 Rxa4 5. b6 Kg8 6. Qc7 Ra1 7.
Rxa1 Rxa1+ 8. Bf1
12-> 1:36 -2.16 1. ... Bc5 2. Rxc5 bxc5 3. Qxc5+ Kf7
4. Rc1 Rxa4 5. b6 Kg8 6. Qc7 Ra1 7.
Rxa1 Rxa1+ 8. Bf1
13-> 4:12 -2.30 1. ... Bc5 2. Rxc5 bxc5 3. Qxc5+ Kg8
4. Rc1 Rxa4 5. b6 Ra1 6. Rxa1 Rxa1+
7. Kh2 Ra2 8. Kg1 Qf7
14 7:58 -2.33 1. ... Bc5 2. Qxd7 Bxd7 3. Rab1 Rxa4
4. Nd2 R4a5 5. f4 exf4 6. gxf4 Bxb5
7. Nc4 Bxc4 8. Rxc4 Kf7 9. e5 Re8
and for Bc3
11-> 12.57 -1.94 1. ... Bc3 2. Qxb6 Bxa1 3. Rc7 Qd8
4. Qc5+ Kg8 5. Rg7+ Kh8 6. Ng5 Bg8
<HT>
12 22.89 -- 1. ... Bc3
12 1:17 -1.13 1. ... Bc3 2. Qxb6 Kg8 3. Kh2 g5 4.
Ra3 Rxa4 5. Rxa4 Rxa4 6. Qc5 Ra5 7.
Kg1 Rxb5
12-> 1:17 -1.13 1. ... Bc3 2. Qxb6 Kg8 3. Kh2 g5 4.
Ra3 Rxa4 5. Rxa4 Rxa4 6. Qc5 Ra5 7.
Kg1 Rxb5
13-> 2:45 -1.23 1. ... Bc3 2. Qxb6 Kg8 3. Ra3 Rxa4
4. Rxa4 Rxa4 5. Rb1 Rb4 6. Rxb4 Bxb4
7. g4 g5 8. Bf1 Qe7
14-> 6:13 -1.18 1. ... Bc3 2. Qxb6 Kg8 3. Nh2 Rxa4
4. Rxa4 Rxa4 5. f4 exf4 6. gxf4 Rb4
7. f5 gxf5 8. exf5 Bxf5 9. Qxb7 Rxb5
10. Qxd7 Bxd7
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.