Playing White in a recent blitz game I reached the position shown in the first diagram. This is a Classical French with the extra moves h4 and ...h6 thrown in, a small detail that will improve White's attacking chances should Black decide to castle kingside. On the reasonable assumption that his king would soon go the other way, I repositioned my queen in order to create some attacking chances.
13.Qe3!? 0-0-0 14.f5!?
It was objectively stronger to maintain positional pressure with 14.Kb1 Kb8 15.a3 Bc8 16.h5, but one cannot apply tournament standards to a blitz game.
14...d4 15.Nxd4 Nxd4?
The correct defence was 15...exf5 16.Nd5 Qxe5 17.Nb6+ Kc7 18.Nd5+ Kc8 and neither side can advantageously avoid the draw by repetition; for example, the cheeky 18...Kd6!? is met by 19.Qc3.
16.Rxd4 Bc6 (second diagram)
It was objectively stronger to maintain positional pressure with 14.Kb1 Kb8 15.a3 Bc8 16.h5, but one cannot apply tournament standards to a blitz game.
14...d4 15.Nxd4 Nxd4?
The correct defence was 15...exf5 16.Nd5 Qxe5 17.Nb6+ Kc7 18.Nd5+ Kc8 and neither side can advantageously avoid the draw by repetition; for example, the cheeky 18...Kd6!? is met by 19.Qc3.
16.Rxd4 Bc6 (second diagram)
I suspect Black was quite satisfied here since it looks like he is exchanging my active rook and taking over the d-file. But the unfortunate grouping of pieces on the c-file means that it's suddenly White to play and win!
17.Rc4! Nd7
No better is 17...b6 18.b4 Bd5 19.Rd4 Nd7 20.Nxd5 exd5 21.Bxa6+ Kb8 22.Rxd5.
18.Rxc6+ bxc6
The exchange sacrifice was obvious enough, but now White should not rush to take the a-pawn with check. Instead there is a quiet move available that transforms the capture into a deadly threat:
19.Qa7!
Black's next move is the only defensive try but it is not enough to save the game.
19...Rde8 20.Bxa6+ Kd8 21.Qa8+ 1-0
Black resigned here since he is mated after 21...Nb8 22.Qxb8+ Kd7 23.Rd1+.
17.Rc4! Nd7
No better is 17...b6 18.b4 Bd5 19.Rd4 Nd7 20.Nxd5 exd5 21.Bxa6+ Kb8 22.Rxd5.
18.Rxc6+ bxc6
The exchange sacrifice was obvious enough, but now White should not rush to take the a-pawn with check. Instead there is a quiet move available that transforms the capture into a deadly threat:
19.Qa7!
Black's next move is the only defensive try but it is not enough to save the game.
19...Rde8 20.Bxa6+ Kd8 21.Qa8+ 1-0
Black resigned here since he is mated after 21...Nb8 22.Qxb8+ Kd7 23.Rd1+.