Author: Dan Newman
Date: 16:52:51 05/30/01
Go up one level in this thread
On May 29, 2001 at 14:21:13, Peter Fendrich wrote:
>This position appeared in an ICC game: Guitje - TerraPi
>
>[D]2r3kb/5q1p/4pPp1/1p1pP3/p2P2Q1/PrP5/1P3R1R/2B3K1 w - - 0 42
>
>the last move from Terra was 41... b5
>Some moves earlier when white made g6, Terra decided to move the bishop from g7
>to h8.
>Both Rb3 and Bh8 are locked in and Terra is absolutely unaware of the
>hopeless situation. Yes, Terra lost...
>
>I see two different but connected problems for computer programs here:
> - the closed position itself
> - the two blocked pieces.
>
>How do you solve/avoid positions like this? Terra has about equal eval for this
>position.
>It is of course possible to punish pawn chains like this in order to avoid
>closed positions but is that really a solution and how to deal with blocked
>positions?
>
>//Peter
Shrike gives an eval of +0.71 for this position, but it will take me a while
to figure out exactly why. I would have expected it to favor black since
black has two connected passed pawns to white's one and has pawns in its pawn
shield area. It also has some terms for sliding pieces bearing on the king
and attacking the squares around the king and for pawn's attacking the
squares immediately in front of the king (IIRC). Also, black's pawns are
in three islands whereas white's are in one. All those things must be adding
up to counteract white's negatives. It would be nice to get an even bigger
score in favor of white though. I think .71 might not be big enough for
Shrike to always avoid a position like this as black. In fact Shrike's
score could easily be in black's favor if a few pieces were moved about,
perhaps without changing the essential character of the position...
Anyway I let Shrike think about this position overnight and got this:
Shrike Version 1.59a
2. 82 0.00 1389 Bh6 <TT>
3. 89 0.00 1659 Bh6 Rc7 Rhg2 <QS>
4. 89 0.00 2475 Bh6 Rc7 Rhg2 <QS>
5. 96 0.01 5834 Bh6 Rc7 Rhg2 Rc6 Qg5 <QS>
6. 96 0.02 14106 Bh6 Rc7 Rhg2 Rc6 Qg5 <QS>
7. 96 0.05 30292 Bh6 Rc7 Rhg2 Rc6 Qg5 Rc4 Rf1 <QS>
7+ 97 0.11 60887 Rh6 <Fail High>
7. 101 0.15 82323 Rh6 Rc7 Be3 Rd7 Qg5 Kf8 Rfh2 <QS>
8. 101 0.27 147501 Rh6 Rc7 Be3 Rd7 Qg5 Kf8 Rfh2 <QS>
9+ 119 0.55 311272 Rh6 <Fail High>
9. 149 0.75 429008 Rh6 Rc7 Qh3 Rd7 Rxh7 Qxh7 Qxe6+ Qf7 Qg4 <QS>
10+ 167 1.43 837465 Rh6 <Fail High>
10. 176 1.93 1135542 Rh6 Rc7 Rfh2 Qe8 Qh3 Qf7 Rxg6+ Qxg6+ Rg2 Rc6
Rxg6+ hxg6 Kf2 <QS>
11+ 194 2.86 1683374 Rh6 <Fail High>
11. 219 3.92 2326920 Rh6 Rc7 Rfh2 Qe8 Qh3 Qf7 Rxg6+ Qxg6+ Rg2 Qxg2+
Kxg2 Rc6 Qh5 <QS>
12. 218 5.61 3367324 Rh6 Rc7 Rfh2 Qe8 Qh3 Qf7 Rg2 Bxf6 Rf2 Qe8
exf6 Qf7 <QS>
13+ 236 11.07 6710989 Rh6 <Fail High>
13. 266 18.01 10933955 Rh6 Rc7 Qh3 Rd7 Rg2 Bxf6 Rf2 Qe8 Rxf6 Re7
Rfxg6+ Qxg6+ Rxg6+ hxg6 Bg5 Re8 <QS>
14+ 284 30.71 18765621 Rh6 <Fail High>
14. 358 43.19 26297619 Rh6 Rc7 Rfh2 Qe8 Qh3 Qf7 Rxg6+ Qxg6+ Rg2 Rc6
Rxg6+ hxg6 Qh6 g5 Qxg5+ Kf8 Qh6+ Kg8 Kf2 <QS>
15+ 376 1:12 44170813 Rh6 <Fail High>
15. 395 1:42 62426415 Rh6 Rc7 Rfh2 Qe8 Qh3 Qf7 Rxg6+ Kf8 Qh6+ Ke8
Rg5 Kd8 Rhg2 Kd7 Bf4 Kc6 R5g4 <QS>
16+ 413 2:51 105764826 Rh6 <Fail High>
16. 460 4:18 160677579 Rh6 Rbxc3 bxc3 Rxc3 Bb2 Rc7 Rfh2 Qe8 Qh3 Qf7
Rxg6+ Qxg6+ Rg2 Rc6 Rxg6+ hxg6 Qg4 Kf7 Kf2 <QS>
17+ 478 8:59 337313271 Rh6 <Fail High>
17. 476 11:11 423199211 Rh6 Rbxc3 bxc3 Rxc3 Bb2 Rc7 Rfh2 Qe8 Qh3 Qf7
Rxg6+ Qxg6+ Rg2 Rc6 Bc3 Qxg2+ Qxg2+ Kf7 Qf3 h6
Kf2 <QS>
18+ 494 22:05 837209569 Rh6 <Fail High>
18. 574 37:02 1408047699 Rh6 Rbxc3 bxc3 Rxc3 Bb2 Rc7 Rfh2 Qe8 Qh3 Qf7
Rxg6+ Qxg6+ Rg2 Qxg2+ Qxg2+ Kf7 Qh3 Bxf6 Qh5+ Kf8
exf6 Rc2 Qh6+ Ke8 <QS>
19. 583 2:04:39 4810005625 Rh6 Rc7 Rfh2 Bxf6 Rxh7 Bxe5 Rxf7 Bxh2+ Kxh2 Rxf7
Qxg6+ Kf8 Qxe6 Re7 Bh6+ Ke8 Qg8+ Kd7 Qxd5+ Ke8
Qg2 Kd7 d5 <QS>
20+ 601 4:15:26 9909584801 Rh6 <Fail High>
20. 616 7:17:59 17110869835 Rh6 Rcxc3 bxc3 Rxc3 Bb2 Rc7 Rfh2 Qe8 Qh3 Qf7
Rxg6+ Qxg6+ Rg2 Rc6 Rxg6+ hxg6 f7+ Kxf7 Qxh8 Ke7
Qh7+ Kd8 Qb7 Rc2 Qxb5 <QS>
-Dan.
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.