This is a key moment of the game:
[D]2r4r/p4k2/5p2/2b1pNp1/bpR1P3/6BP/1P1R1PP1/6K1 b - - 4 31
Gaviota (black) played Bb3, which wins material but loses the game after Rxc5 and Rd7+. The rook in 7th proved to completely disrupts blacks game and little by little, white obtained a decisive advantage without much effort. Everything was downhill.
Rather that Bb3, Bb5 seems to win but black needs to see that Rc1 Bxf2+ leaves it with a powerful passed pawn in b4 (needs a deep search to evaluate the consequences).
Rc1 Bxf2+ Kxf2 Rxc1 Nd6+ Ke7 Nxb5 Rd8 Rxd8 Kxd8 Nxa7 Rc2+ and Rxb2
After 70857 seconds and 22 plies (19.6 hours) Gaviota finally sees that Bb3 is wrong and chooses a6 with a +0.70 advantage. Gaviota suffers here from a bad search and lack of good eval to understand R in 7th, (I think).
I think it is an interesting position. Good engines should quickly avoid Bb3, but medium ones... I don't know. What does your engine say?
Code: Select all
analyze
iterative deepening --> start, thread=0
set timer to infinite
65 1: 0.0 +2.87 Bxf2+ 17.Bxf2 Rxc4 18.Bxa7 Rxe4
126 2 0.0 :-(
188 2 0.0 :-(
1460 2: 0.0 +0.81 g4 17.Kh2 gxh3 18.gxh3
3929 3 0.0 :-) Bb3
4907 3: 0.0 +1.31 Bb3 17.Nd6+ Ke6 18.Nxc8 Bxc4
7164 4: 0.0 +1.31 Bb3 17.Nd6+ Ke6 18.Nxc8 Bxc4
19185 5: 0.0 +1.49 Bb3 17.Rxc5 Rxc5 18.Rd7+ Kg6 19.Rg7+
Kh5 20.Rxa7 Rc1+ 21.Kh2
33448 6 0.1 :-(
42673 6: 0.1 +1.64 Bb3 17.Rxc5 Rxc5 18.Rd7+ Kg6 19.Ne7+
Kh5 20.Rxa7 Rc1+ 21.Kh2
56669 7 0.1 :-(
86436 7: 0.1 +1.12 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Rf8 21.f3
120198 8 0.2 +1.05 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Rg8 21.Rb7 Rc2 22.Rxb4
171785 8: 0.2 +1.05 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Rg8 21.Rb7 Rc2 22.Rxb4
236878 9 0.3 +1.05 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Rg8 21.Rb7 Rc2 22.Rxb4
320859 9: 0.5 +1.05 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Rg8 21.Rb7 Rc2 22.Rxb4
496526 10 0.8 +1.00 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Rc2 21.Rb7 Rc1+ 22.Kh2
746942 10: 1.2 +1.00 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Rc2 21.Rb7 Rc1+ 22.Kh2
1080033 11 1.6 +0.98 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Rc2 21.Rb7 Rf8 22.Rxb4
1658021 11: 2.3 +0.98 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Rc2 21.Rb7 Rf8 22.Rxb4
2974212 12 3.5 +0.90 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Kd8 21.Ra6 Rc1+ 22.Kh2 Rc2
23.Rxf6
4736929 12: 5.3 +0.90 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rg8 20.f3 Kd8 21.Ra6 Rc1+ 22.Kh2 Rc2
23.Rxf6
7983408 13 8.6 +0.82 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Kd8 21.Rb7 Be6 22.Rb8+ Rc8
23.Rxb4 Kd7 24.Ne3 Kd6 25.Rd4+ Kc5
12803040 13: 12.1 +0.82 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Rc1+ 20.Kh2 Kd8 21.Rb7 Be6 22.Rb8+ Rc8
23.Rxb4 Kd7 24.Ne3 Kd6 25.Rd4+ Kc5
21403062 14 19.2 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Rc1+ 21.Kh2 Re8 22.Bf2 Re6
23.Rb7 Rc2 24.Rxb4
35487124 14: 26.6 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Rc1+ 21.Kh2 Re8 22.Bf2 Re6
23.Rb7 Rc2 24.Rxb4
65804053 15 43.2 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Be6 21.Nd6 Rc1+ 22.Kh2 Rh6
23.Bf2 Rc6 24.Bc5 b3
117211435 15: 65.0 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Be6 21.Nd6 Rc1+ 22.Kh2 Rh6
23.Bf2 Rc6 24.Bc5 b3
192115289 16 98.3 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Be6 21.Nd6 Rc1+ 22.Kh2 Rh6
23.Bf2 Rc6 24.Bc5 b3 25.Ra8+ Kd7
26.Ra7+ Kd8
310534273 16: 141.4 +0.73 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Be6 21.Nd6 Rc1+ 22.Kh2 Rh6
23.Bf2 Rc6 24.Bc5 b3 25.Ra8+ Kd7
26.Ra7+ Kd8
591801860 17 244.1 +0.71 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Rc1+ 21.Kh2 Re8 22.Bf2 Re6
23.Rb7 Rc2 24.Rb8+ Kc7 25.Rxb4 Rxb2
26.Kg3
1226828822 17: 439.6 +0.71 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f3 Rc1+ 21.Kh2 Re8 22.Bf2 Re6
23.Rb7 Rc2 24.Rb8+ Kc7 25.Rxb4 Rxb2
26.Kg3
2256675147 18 763.0 +0.55 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Kb5 27.Nd6+ Kc5 28.Rc7+ Kxd6
29.Rxc1
4287883550 18: 1344.0 +0.55 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Kb5 27.Nd6+ Kc5 28.Rc7+ Kxd6
29.Rxc1
8361297116 19 2517.8 +0.46 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kc5 28.Nxg8 Bxg8
29.Ra8
16543216776 19: 4760.8 +0.46 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kc5 28.Nxg8 Bxg8
29.Ra8
28436268565 20 8008.7 +0.48 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kb5 28.Nxg8 Bxg8
29.h4 Rd2 30.hxg5 fxg5
61611953501 20: 16852.5 +0.48 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kb5 28.Nxg8 Bxg8
29.h4 Rd2 30.hxg5 fxg5
115660769637 21 31134.6 +0.53 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kb5 28.Nxg8 Bxg8
29.h4 gxh4 30.Kh3
239191996745 21: 63389.0 +0.53 Bb3 17.Rxc5 Rxc5 18.Rd7+ Ke8 19.Rxa7
Kd8 20.f4 exf4 21.Bf2 Rc1+ 22.Kh2 Rg8
23.Bb6+ Ke8 24.Ra8+ Kd7 25.Ra7+ Kc6
26.Ba5 Rd1 27.Ne7+ Kb5 28.Nxg8 Bxg8
29.h4 gxh4 30.Kh3
267151688241 22 70857.3 :-( Bb3
525502221343 22 139409.4 +0.70 a6 17.Kh2 Bb5 18.Rc1 b3 19.Rcd1 g4
20.h4 Bb4 21.Nd6+ Bxd6 22.Rxd6 Rc2
23.R1d2 Ke7 24.f3 gxf3 25.gxf3 a5
26.Bf2 a4 27.R6d5 Kf7 28.Kh3