Saturday, January 13, 2018

Jerome Gambit: Choosing Better or Worse?

Sometimes a computer chess engine will recommend a line of play which is "objectively" better than an alternative that a human might choose. Yet there might be good reasons to choose the "worse" line of play, if it is tricky and has some traps. See the note to Black's 7th move.

On the other hand, sometimes "human" moves fall short, as well. See the note to Black's 9th move.

Wall, Bill - Guest902091, 2017

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Nf6 

Black has so many ways to return some of the sacrificed material!

7.dxe5 Bxf2+ 

This move appears in 10 previous games appearing in The Database, with White scoring 70%. However, that is not the whole story.

Stockfish 8 recommends, instead 7...Qe7!?, which does not show up in any of the games in The Database. White does best to grab a second piece with 8.exf6, but then is faced with how to answer 8...Qxe4+.

Probably best is 9.Kf1 which we will come back to in a moment, after first examining the messy 9.Be3.

Black can respond to this latter move with 9...Bxe3 10.fxe3 Qxe3+ 11.Qe2 when the exchange of Queens would leave him a pawn up. Or he could go for 11...Qc1+ when 12.Kf2 is the offer of a Rook, i.e. 12...Qxh1, although it does not turn out well for the second player: 13.Qe7+ Kg6 14.Qxg7+ Kf5 15.Nc3 Qxh2 (taking the other Rook with 15...Qxa1 leads to mate) 16.Rf1 and Black's position is miserable as he has only 16...Qf4+ to help him extend the game, but 17.Kg1 Qxf1+ 18.Kxf1 still is hopeless. After visiting c1, Black's Queen should return to f4 with check, and eventually wind up a pawn ahead, again. 

Going back to the computer-recommended 9.Kf1, Black responds with 9...Qf5 and after 10.Qf3 Qxf3 11.gxf3 d5!? he is a bit better (better pawn structure, two Bishops, equally insecure Kings) even if White finds 12.h4!? to prevent ...Bh3+, forcing his King into the center where the enemy Rooks can roam.

By the way, Bill dispatched 7...Nxe4 quickly in a couple of games: Wall,B - NN,, 2016 (1-0, 16) and Wall,B - TenAndOnly10,, 2016 (1-0, 21)

8.Kxf2 Nxe4+ 9.Kg1 Rf8 

Preparing to castle-by-hand, a standard defensive plan in the Jerome Gambit; but overlooking the Queen check at d5 - odd, in that his Bishop sacrifice seemed aimed against that same eventuality.

Instead, 9...d5 would be about even, although Bill has a couple of wins against the move:  Wall,B - MyDrunkAccount,, 2016 (1-0, 20) and Wall,B - Szachowski,, 2017 (1-0, 20). 

10.Qd5+ Ke8 11.Qxe4 Rf7 12.Nc3 d6 

This hurries Black's demise.

13.exd6+ Kf8 14.Qxh7 Qxd6 15.Qh8+ Ke7 16.Bg5+ Kd7 17.Rd1 Black resigned

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