Protect Which Pawn?

Here we have another human vs computer game (see "Irrational"), one which turns, curiously, on computer "psychology" and a subtle anti-computer strategy. Again, it is the human who applies brutal tactical force to close out the game.

Wall, Bill - Comet B50 engine
Palm Bay, FL, 2015

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.Qh5+ Ke6 7.f4 d6

Ah, yes, back to the "annoying" or "silicon" defense.

Black will soon be challenged to decide which pawn(s) it wants to protect, and which one(s) it wants to let go. This is something White can take advantage of, if he pushes it.

8.fxe5 dxe5 9.Qh3+ Ke7 

Ten years ago this position proved uneasy for the computer playing the Jerome Gambit, and it quickly decided to save half a point: 9...Kd6 10.Qd3+ Ke7 11.Qg3 Kd6 12.Qd3+ Ke7 13.Qg3 Kd6 14.Qd3+ drawn, Crafty 19.19 - RevvedUp, blitz 2 12, 2006. 

10.Qg3 Kd6 11.Qd3+ Bd4 

Again, here, in the human - computer supermatch played a decade ago, the computer, with the Jerome Gambit, decided to bail out: 11...Ke7 12.Qg3 Ke6 13.Qh3+ Kf7 14.Qh5+ Ke6 15.Qh3+ drawn, Hiarcs 8 - RevvedUp, blitz 2 12, 2006).

Upon reflection, the g7 pawn is probably more valuable than the e5 pawn, despite the Comet B50's evaluations and calculations, and ...Kd6 is not Black's strongest continuation. Here it will cost a piece.

(On the other hand, most computers opening with the Jerome Gambit as White would probably love to offer and receive a draw after four moves!)

12.c3 Qg5

Comet B50 goes for wild tactics. It is interesting to recall two historical games that showed the computer (in this case, an early version of Fritz) solidly surrendering the piece: 12...c5 13.cxd4 cxd4 14.b3 Kc7 (14...Nf6 15.Ba3+ Kc7 16.Qg3 Re8 17.Qxg7+ Kb8 18.d3 Qa5+ 19.b4 Qb6 20.O-O Re6 21.Nd2 Qd8 22.Nc4 Qg8 23.Qxg8 Nxg8 24.Rf5 Ne7 25.Rxe5 Rxe5 26.Nxe5 Ng6 27.Nf3 Nf4 28.b5 Kc7 29.Ne5 Ng6 30.Nxg6 hxg6 31.Bc5 Bd7 32.a4 Re8 33.Bxd4 a6 34.bxa6 bxa6 35.a5 Kd6 36.Bb6 Bc6 37.Ba7 Bb5 38.Rd1 Ke5 39.Kf2 Ra8 40.Bb6 Ba4 41.Ra1 Bc6 42.Ke3 Re8 43.d4+ Kd6 44.e5+ Kd7 45.g3 Rf8 46.Rd1 Ke6 47.Rd3 Rf1 48.Rc3 Rf3+ 49.Kd2 Rxc3 50.Kxc3 Kd5 51.h4 Ke4 52.Kc4 Bb5+ 53.Kc5 Kf3 54.d5 Kxg3 55.e6 Kxh4 56.d6 Kg5 57.d7 Kf5 58.d8=Q Kxe6 59.Qg8+ Kf5 60.Qd5+ Kf6 61.Kd6 Kg7 62.Qxb5 axb5 63.a6 b4 64.a7 g5 65.a8=Q g4 66.Qe4 g3 67.Qxb4 Kf7 68.Qf4+ Kg6 69.Qg4+ Kh6 70.Qg8 Kh5 71.Bd8 Kh6 72.Qg5+ Kh7 73.Bf6 g2 74.Qg7 checkmate, Fisher-Kirshner,M - Knight Stalker, Fremont, CA, 1993) 15.Qc4+ Kb8 16.Ba3 Qh4+ 17.Kd1 Qh6 18.Qd5 Bg4+ 19.Ke1 Qh4+ 20.g3 Qg5 21.Bd6+ Kc8 22.Qf7 Bd7 23.Na3 Kd8 24.Rc1 Ne7 25.Rf1 Rc8 26.Rxc8+ Nxc8 27.Nc4 Re8 28.Bb4 Qh6 29.Na5 b6 30.Nc4 Bc6 31.d3 Qc1+ 32.Kf2 Qc2+ 33.Kg1 Qxd3 34.Nd6 Qe3+ 35.Rf2 Nxd6 36.Bxd6 Bd7 37.Kg2 Qxe4+ 38.Kf1 Bh3+ 39.Rg2 Qxg2+ 40.Ke1 Qh1+ 41.Kd2 Qxh2+ 42.Ke1 Qxg3+ 43.Kd2 Qc3+ 44.Ke2 d3+ 45.Kf2 Qb2+ 46.Kg3 Qg2+ 47.Kh4 Qg4 checkmate, Fisher-Kirshner,M - Knight Stalker, Fremont, CA, 1993. 

13.cxd4 Qxg2 14.dxe5+ 

14...Kxe5

The King would be relatively safer on e7. 

15.Qd5+ Kf6

The Queen is now lost, but otherwise Black loses her and his King: 15...Kf4 16.d4+ Kf3 17.Nd2+ Kg4 18.h3+ Qxh3 19.Rxh3 Kxh3 20.Qh5+ Kg2 21.Qf3+ Kh2 22.Nf1+ Kg1 23.Be3 checkmate.

analysis diagram






16.e5+ Black resigned