Does anyones computer find RxH2

Discussion of anything and everything relating to chess playing software and machines.

Moderators: hgm, Rebel, chrisw

User avatar
mhurd
Posts: 46
Joined: Wed Dec 30, 2009 9:27 pm

Re: Does anyones computer find RxH2

Post by mhurd »

I think it was meant as a best variation after Rxh2. Rxh2 is in Rainbow Serpent's movelist continuously near the top but never considered very long. Apparently not enough compensation to compete with Qc5, but that does not get a winning score so in the end it is still a positional decision, unless the score for Rxh2 is losing, have not really tried the move but I don't think it is losing?
That is correct, I used stockfish to see what might have been played after Rxh2 perhaps I should have made this clear. :roll:

Mike
Top
User avatar
Eelco de Groot
Posts: 4567
Joined: Sun Mar 12, 2006 2:40 am
Full name:   

Re: Does anyones computer find RxH2

Post by Eelco de Groot »

mhurd wrote:
I think it was meant as a best variation after Rxh2. Rxh2 is in Rainbow Serpent's movelist continuously near the top but never considered very long. Apparently not enough compensation to compete with Qc5, but that does not get a winning score so in the end it is still a positional decision, unless the score for Rxh2 is losing, have not really tried the move but I don't think it is losing?
That is correct, I used stockfish to see what might have been played after Rxh2 perhaps I should have made this clear. :roll:

Mike
Thanks Louis and Mike!

As a follow up just some more computer analysis I made, to see if the computer can look deep enough in the Rook endgame after the Qc5 choice, I think it may be won but a computerprogram would have to look very very deep indeed to show enough progress, and maybe there are some side variations that would actually save White, but anyway looking deeper the score is reasonably steady going up for Black. Shaving off some bits of the search in Rainbow Serpent in the process hoping this version can look a bit deeper even with limited resources. There were some stupid bugs in the nextBestMove code eliminated. Version 044:


Engine: Rainbow Serpent 1.8(s)dc Build 044 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski

1.00 0:00 -0.44 1...gxf4 (5.410) 21

2.00 0:00 -0.44 1...gxf4 2.Bxf4 (5.479) 21

2.00 0:00 -0.41 1...Qc5 2.Rhf1 (8.855) 35

3.00 0:00 0.00 1...Qc5 2.Qf3 Kb7 (16.713) 63

4.00 0:00 0.00 1...Qc5 2.Qf3 Nf2 3.Bg1 (32.208) 114

5.00 0:00 +0.32 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 Rxh2 6.Bxc6 (51.723) 165

6.00 0:00 +0.20 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 Rxh2 6.Bf3 (69.652) 203

6.00 0:00 +0.29 1...Rxh2 2.Rxh2 gxf4 3.Qf3 Re8 (218.969) 369

7.00 0:00 +0.33 1...Rxh2 2.Rxh2 gxf4 3.Qe1 Rc8 (232.429) 371

7.00 0:00 +0.70++ 1...Qc5 2.Qxc5 (243.876) 381

7.00 0:00 +0.92++ 1...Qc5 2.Qxc5 (245.347) 374

7.00 0:00 +1.30++ 1...Qc5 2.Qxc5 (249.164) 379

7.00 0:00 +1.85 1...Qc5 2.Qe2 Nf2 3.fxg5 Nxd1 4.Qxd1 (261.922) 389

8.00 0:00 +2.07 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxf4
7.Rd4 Rh3 (359.763) 426

9.00 0:00 +1.11 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.fxg5 Rxh2
7.Rd8+ Kb7 8.b4 (400.453) 442

10.01 0:01 +2.31 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Re1 Bf2
7.Rf1 Rh4 (497.999) 468

11.01 0:01 +2.07 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxf4
7.g4 Bc1 (645.152) 497

12.01 0:01 +1.49 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Rf1 Rf8 9.b3 f3 10.Kb2 (770.865) 513

13.01 0:01 +1.49 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Rf1 Rf8 9.b3 f3 10.Kb2 fxg2 (1.023.440) 545

14.01 0:02 +1.29 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Rf1 Rf8 9.Kc1 e3
10.Rh1 Rg8 11.Rh4 (1.197.998) 563

15.01 0:02 +1.59 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Rf1 e3 9.Ka2 Rh2
10.Rxf4 Rh3 (1.494.713) 579

16.01 0:03 +1.41 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Rf1 e3 9.Kc1 e2 10.Rg1 Rh5
11.Re1 Rh2 (2.018.995) 601

17.01 0:04 +1.46 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Kb7 9.Rf1 e3
10.Kd1 Rd8+ 11.Ke1 Rd2 12.Rxf4 c5 (3.009.046) 621

18.01 0:06 +1.57 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.b3 e3 11.Kd1 Kb7 12.Ke1 Kb6
13.Rh1 (4.087.876) 632

19.01 0:08 +1.53 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.b3 Kc8 11.a4 Kd7 12.Kb2 Ke7
13.Kc3 (5.490.307) 633

20.01 0:11 +1.73 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 Rg4
10.Re1 e3 11.Rf1 Kb7 12.g3 fxg3
13.Ke2 Rh4 14.Kf3 (7.466.059) 647

21.01 0:17 +1.65 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 Rg4 (11.456.744) 661

22.01 0:25 +1.45-- 1...Qc5 2.Qxc5 (17.248.464) 669

22.01 0:37 +1.49 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 Rg4
10.Re1 e3 11.Rf1 Kb7 12.g3 fxg3
13.Rg1 Rg5 14.Ke2 Kb6 (25.061.939) 676

23.01 0:40 +1.61 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 Rg5
10.Rf1 Rg4 11.Ke1 Kb7 12.Kf2 Rg5
13.Re1 (27.585.251) 678

24.01 1:03 +1.47 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 Rg5
10.Rf1 Rg4 11.Ke1 Kb7 12.Kf2 Rg5
13.Re1 (43.542.395) 688

25.01 1:50 +1.88++ 1...Qc5 2.Qxc5 (75.160.800) 680

25.01 1:57 +2.08++ 1...Qc5 2.Qxc5 (79.751.078) 680

25.01 2:00 +2.14 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rd8 9.Rf1 e3 10.b4 Rd5
11.c4 Rxe5 12.Kc2 Kb7 13.Kd3 e2
14.Re1 Re3+ (82.016.735) 680

26.01 2:56 +1.85 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 f3
10.Ke1 e3 11.Rf1 fxg2 12.Rg1 Rg3
13.Ke2 Kb7 14.b4 Kb6 (119.647.747) 677

27.01 4:17 +1.93 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 f3
10.Ke1 e3 11.Rf1 fxg2 12.Rg1 Kb7
13.Ke2 Rg3 (174.432.754) 676

28.01 6:57 +1.93 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd1 f3
10.Ke1 e3 11.Rf1 fxg2 12.Rg1 Kb7
13.Ke2 Rg3 (280.568.733) 672

29.01 10:02 +1.85-- 1...Qc5 2.Qxc5 (405.982.822) 673

29.01 18:24 +1.77-- 1...Qc5 2.Qxc5 (744.536.928) 674

29.01 21:21 +2.10++ 1...Qc5 2.Qxc5 (861.677.648) 672

29.01 21:24 +1.77 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.Kd1 Kb7 11.Re1 e3 12.Rf1 Kb6
13.g3 fxg3 14.Ke2 g2 (863.883.703) 672

30.01 22:51 +2.10++ 1...Qc5 2.Qxc5 (919.187.271) 670

30.01 23:18 +2.10 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd2 Rg5
10.g4 Kb7 11.c4 a5 12.b3 Kb6 13.Kc3 c5
14.Kd2 Kc6 (938.841.890) 671

31.01 28:21 +2.10 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd2 Rg5
10.g4 Kb7 (1.137.853.987) 668

32.01 48:50 +2.06 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Kd2 Kb7
10.Ke2 Kb6 11.Kf2 Kc5 12.Rd1 Rg5
13.b4+ Kc4 14.Rd7 Rg3 (1.945.091.445) 663

33.01 99:31 +2.22++ 1...Qc5 2.Qxc5 (3.963.881.623) 663

33.01 100:25 +2.18 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.Kd1 Kb7 11.Ke1 Kb6 12.Kf2 Kc5
13.Rd1 Rg5 14.b4+ Kc4 (4.003.038.738) 664

34.01 183:30 +2.02-- 1...Qc5 2.Qxc5 (7.296.921.475) 662

34.01 369:21 +2.32 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.Kd1 Kb7 11.Ke1 Kb6 (14.570.963.075) 657

35.01 438:38 +2.34 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+
4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1
7.Rxg1 gxf4 8.Kc1 Rg8 9.Rf1 Rg4
10.Kd1 Kb7 11.Ke1 Kb6 12.Kf2 Kc5
13.Rd1 Rg5
{[D]8/p1p5/2p1p3/2k1P1r1/4pp2/P7/1PP2KP1/3R4 w - - 0 1
This may be won for Black but only slow progress is
visible. F.e. 14. c3 Rxe5 15. Rd4 Kb5 16. Rb4+ Ka6
17. Ra4+ Kb7 18. Rb4+ Kc8 19. Ra4 c5 is possible
[D]2k5/p1p5/4p3/2p1r3/R3pp2/P1P5/1P3KP1/8 w - - 0 1
This is evaluated -2.94 for White but starting a new
search here Rainbow Serpent gives 20. Rc4 Kb7 21. b4 Kc6
and this is evaluated -3.63 at 32 plies} (17.352.194.857) 659

best move: Qe7-c5 time: 547:17.203 min n/s: 658.963 nodes: 21.638.512.215

Version 041 was:

Code: Select all

      // Step extra. pv search (only in PV nodes)
      // The first move in list is the expected PV
      if (PvNode && (moveCount == 1 || (move == nextbestMove && !singularExtended)))
	  {
		  if &#40;newDepth < 10*OnePly&#41;
			  value = - search<NonPV>&#40;pos, ss+1, -Max&#40;alpha+1, excValue+1&#41;, -Max&#40;alpha, excValue&#41;, newDepth + 4*OnePly, ply+1&#41;;

          if &#40;moveCount == 1&#41;
			  value = newDepth < OnePly ? -qsearch<PV>&#40;pos, ss+1, -beta, -alpha, Depth&#40;0&#41;, ply+1&#41;
                                    &#58; - search<PV>&#40;pos, ss+1, -beta, -alpha, newDepth, ply+1&#41;;
	  &#125;
      else
      &#123;
          // Step 14. Reduced depth search
          // If the move fails high will be re-searched at full depth.
Changed it to

Code: Select all

      // Step extra. pv search &#40;only in PV nodes&#41;
      // The first move in list is the expected PV
      if &#40;PvNode && &#40;moveCount == 1 || move == nextbestMove&#41;)
	  &#123;
		  if &#40;newDepth < 10*OnePly || move == nextbestMove&#41;
			  value = - search<NonPV>&#40;pos, ss+1, -Max&#40;alpha+1, excValue+1&#41;, -Max&#40;alpha, excValue&#41;, newDepth + 4*OnePly, ply+1&#41;;

          if &#40;moveCount == 1 || value > alpha&#41; 
			  value = newDepth < OnePly ? -qsearch<PV>&#40;pos, ss+1, -beta, -alpha, Depth&#40;0&#41;, ply+1&#41;
                                    &#58; - search<PV>&#40;pos, ss+1, -beta, -alpha, newDepth, ply+1&#41;;
	  &#125;
      else
      &#123;
          // Step 14. Reduced depth search
          // If the move fails high will be re-searched at full depth.
because in the old version, only if newDepth was smaller than 10 plies there actually was a search done for nextbestMove and if the nextbestMovemove failed high, result of the deep nullwindow search > alpha, there would be no re-search! So this should be a bit more accurate
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
Top
rightrook
Posts: 1452
Joined: Wed Mar 08, 2006 8:45 pm

Re: Does anyones computer find RxH2

Post by rightrook »

Crafty 19.19 finds Rxh2 in only 25 seconds!

(on my slow Compaq)...

:lol:

All the other engines I tried have trouble with this one!

Thanks for the good test move!
Robert
Top
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: Does anyones computer find RxH2

Post by zullil »

rightrook wrote:Crafty 19.19 finds Rxh2 in only 25 seconds!

(on my slow Compaq)...

:lol:

All the other engines I tried have trouble with this one!

Thanks for the good test move!
Robert
I think the point is that Rxh2 is not the right move. :cry: In any case, see what Crafty-23.3 liked: http://talkchess.com/forum/viewtopic.ph ... 52&t=35915
Top
kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 4:19 pm

Re: Does anyones computer find RxH2

Post by kgburcham »

and another version of Crafty 23.01 shows Rxh2 second best move.

[D] 1k1r1b1r/p1p1q3/2p1p3/4Ppp1/4nP2/P2BQ3/1PP3PB/2KR3R b - - 0 1

Crafty 23.01:

1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-2.18) Depth: 15/26 00:00:00 8381kN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Rh1 7.fxg5 Rxg1 8.Rxg1 Bxg1 (-2.29) Depth: 16/33 00:00:01 17675kN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-2.12) Depth: 17/32 00:00:02 27014kN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-1.99) Depth: 18/31 00:00:04 44770kN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-2.11) Depth: 19/37 00:00:09 95689kN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 e3 (-2.25) Depth: 20/38 00:00:17 177mN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-1.98) Depth: 21/38 00:00:30 310mN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Rf1 Rh4 (-2.07) Depth: 22/41 00:01:02 639mN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Kc1 Rg8 (-2.27) Depth: 23/44 00:02:14 1354mN
1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Kc1 Rd8 (-2.20) Depth: 24/47 00:04:16 2576mN


Crafty 23.01:

1. -+ (-2.20): 1...Qc5 2.Qxc5 Bxc5 3.Bxe4 Be3+ 4.Kb1 Rxd1+ 5.Rxd1 fxe4 6.Bg1 Bxg1 7.Rxg1 gxf4 8.Kc1 Rd8
2. -/+ (-0.99): 1...Rxh2 2.Rxh2 Qxa3 3.bxa3 Bxa3+ 4.Kb1 Nc3+ 5.Ka1 Bb2+ 6.Kxb2 Nxd1+ 7.Kc1 Nxe3 8.fxg5 Ng4
3. +- (1.63): 1...Rd5 2.Bxe4 fxe4 3.Bg3 gxf4 4.Bxf4 Qg7 5.Rxh8 Qxh8 6.Qxe4 Bh6 7.g3 Bxf4+ 8.gxf4 Qh2
Top

Return to “Computer Chess Club: General Topics”