On the surface, the following Blackburne Shilling Jerome Gambit is clear enough: White plays a recommended 8th move and checkmates his opponent on move 13. Yet, a peek at the notes - at what could have been played - is a bit head-spinning. The game turns out to have been a suspension bridge over churning, raging waters.
foko - borodin
FICS, 2019
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4
The Blackburne Shilling Gambit.
4.Bxf7+
The Blackburne Shilling Jerome Gambit.
4...Kxf7 5.Nxe5+ Ke6 6.c3
Probably the strongest continuation for White.
6...Kxe5 7.cxd4+ Kxd4
Black's pawn capture is risky; he would do better to head to safety with 7...Ke6. Still, with the move Black throws down the gauntlet: Can you punish me for this pawn grab?
8.Qb3
White has tried 8.d3 (see here, here, here and here), as well as 8.Nc3. I have recommended 8.Qb3, but it had remained unplayed - until it was seen 3 times in The Database in 2019.
Although Black's King looks vulnerable, play can become complicated, and White needs to realize that often his Queen has to go to f7 to help tighten a checkmating net. Earlier in the year, foko had played 8.Qb3 against sabishii in a standard FICS game, and after many changes of fortune, Black finally won in 55 moves.
I have to admit, I would probably play 8.d3 the next time I faced this line.
8...Ke5 9.Qd5+
Stockfish 10 likes 9.Qf7, while Komodo 10 likes 9.d4+ Kf6 (9...Kxd4 10.Qd5#; 9...Kxe4 10.Qf3+ Kxd4 11.Qf5 d5 12.Be3+ Kc4 13.Na3+ Kb4 14.Qd3 Qe8 15.Qc3+ Ka4 16.b3+ Kxa3 17.Qa5+ Kb2 18.Rb1+ Kxb1 19.Kd2+ Kb2 20.Bd4#) 10.Qf3+. Both agree that the text gives Black a slight edge.
9...Kf6
10.d4
More solid was 10.d3.
Leading to wacky complications - not a quick draw by repetition - is 10.Qf5+, e.g. 10...Ke7 11.Qe5+ Kf7 12.Qd5+ Ke8 13.Qh5+ g6 14.Qe5+ Qe7 15.Qxh8 Qxe4+ 16.Kd1 Qxg2 17.Re1+ Kf7 18.Qxh7+ Bg7 19.Qh4 Qf3+ 20.Kc2 Qc6+ 21.Nc3 d5 22.Qb4 Be6 and perhaps Black has an edge...
10...Qe8
This clears things up. Black could have lurched ahead with 10...Ne7.
11.Bg5+ Kg6 12.Qf5+ Kh5 13.g4 checkmate