Deep Sjeng wins two games vs Rybka test positions

[kgburcham]

21.Bxh5
[d] 2rr2k1/1bq1bp2/p3p1p1/1pnpP1Pp/3B1PBQ/P1N2R2/1PP4P/3R2K1 w - -


23.b4
[d] 2rr1bk1/1bq2p2/p3p3/1pnpP1PQ/3B1P2/P1N2R2/1PP4P/3R2K1 w - -


53.Qg3
[d] 2r2k2/3bn2r/q2p4/1p1PppB1/1P1bP3/5Q1P/4B2R/3N1R1K w - -

[AdminX]

I did not give it a long time (Under 5 Minutes) to think, but here is what I got. In Position number 2 it did not find b4, however it liked Rh3 better. So I showed b4 to it and it quickly showed by eval that b4 was the better move.

[d]2rr2k1/1bq1bp2/p3p1p1/1pnpP1Pp/3B1PBQ/P1N2R2/1PP4P/3R2K1 w - - 0 1

Analysis by 64-bit Rybka 2.3.2a mp :

1.Rh3 Kf8 2.Be2 Ne4 3.b4 Kg7 4.Qe1 Bc6 5.Bf3 Qb7 6.Qe3 Rc7
= (-0.18) Depth: 5 00:00:00
= (-0.17) Depth: 15 00:00:07 2670kN
1.Bxh5 gxh5 2.Qxh5 Bf8 3.Rh3 Bg7 4.b4 Ne4 5.Qh7+ Kf8 6.Rhd3 Nxc3 7.Rxc3 Qxc3
= (0.00) Depth: 15 00:00:08 3364kN
= (0.00) Depth: 18 00:00:22 9115kN

[d]2rr1bk1/1bq2p2/p3p3/1pnpP1PQ/3B1P2/P1N2R2/1PP4P/3R2K1 w - - 0 1

Analysis by 64-bit Rybka 2.3.2a mp :

1.f5 exf5 2.Rh3
=/+ (-0.45) Depth: 5 00:00:00
=/+ (-0.62) Depth: 6 00:00:00 13kN
1.Kg2 Bg7 2.Rh3 Qe7 3.Qh7+ Kf8 4.Rf3 Ne4 5.h4 Nxc3
=/+ (-0.57) Depth: 6 00:00:00 28kN
=/+ (-0.64) Depth: 11 00:00:01 477kN
1.f5 exf5 2.e6 fxe6 3.Qh8+ Kf7 4.b4 Ke8 5.bxc5 Qe7 6.g6 Kd7 7.Kf1 Qg5
+/- (0.73) Depth: 11 00:00:02 816kN
+/= (0.42) Depth: 19 00:01:28 41852kN
1.Rh3 Bg7 2.Ne2 Kf8 3.f5 Bxe5 4.b4 Bxd4+ 5.Nxd4 Ne4 6.fxe6 Qf4 7.Rf1 Qxg5+
+- (1.58) Depth: 19 00:02:45 68962kN
+- (1.62) Depth: 21 00:03:57 94448kN

[d]2r2k2/3bn2r/q2p4/1p1PppB1/1P1bP3/5Q1P/4B2R/3N1R1K w - - 0 1

Analysis by 64-bit Rybka 2.3.2a mp :

1.exf5 Nxd5 2.Nf2
= (0.00) Depth: 5 00:00:00
=/+ (-0.58) Depth: 6 00:00:00 33kN
1.Ne3 f4 2.Ng4
=/+ (-0.36) Depth: 6 00:00:00 43kN
1.Qd3 Qa4 2.Bxe7+ Kxe7 3.exf5 Qc2
=/+ (-0.34) Depth: 6 00:00:00 85kN
=/+ (-0.34) Depth: 7 00:00:00 109kN
1.Ne3 f4 2.Ng4 Rc3
= (-0.25) Depth: 7 00:00:00 117kN
1.Bxe7+ Kxe7 2.exf5 Rch8 3.Bd3 Kd8 4.Ne3 Rh4
= (-0.07) Depth: 7 00:00:00 127kN
= (-0.08) Depth: 9 00:00:01 198kN
1.Bd3 Qa3 2.Bxe7+ Rxe7 3.Qh5 Qxd3 4.Qh8+ Kf7 5.Qh7+ Kf8 6.Rxf5+ Bxf5 7.Qxf5+ Rf7
= (0.13) Depth: 9 00:00:01 338kN
= (0.00) Depth: 18 00:01:06 22098kN
1.Qg3 f4 2.Bxe7+ Rxe7 3.Qh4 Rf7 4.Qh6+ Ke7 5.Bh5 Rg8 6.Bxf7 Kxf7 7.Rc2 Rg7
+/= (0.30) Depth: 18 00:01:51 40560kN

[Uri]

23.b4

[d] 2rr1bk1/1bq2p2/p3p3/1pnpP1PQ/3B1P2/P1N2R2/1PP4P/3R2K1 w -

But why is b4 the best move? b4 just drives the knight away either to e4 so that white can play Rdd3. But why not start a kingside attack right away with f5?

[jdart]

Can you also post the games?

--Jon