A bolt from the blue

The following game was played in the ICC 5-minute pool against an opponent whose FIDE rating is 2071. I don’t normally annotate or show blitz games that I’ve played for obvious quality reasons, but I uncorked an extremely snazzy tactic in this game that I can’t help but share. (To my opponent’s credit, he was very gracious and also congratulated me on the move.) A steady diet of exercises based on ‘invisible’ moves seems to have finally paid off!

*Spoiler alert* The key positions is after White plays 18.g3, so you can try to work it out for yourself if you like! Of course, knowing ahead of time the critical moment makes any tactic easier to spot, which is part of why finding moves like this can be so difficult!

[Event "5-minute pool"]
[Site "Internet Chess Club"]
[Date "2013.05.14"]
[Round "?"]
[White "Pavel"]
[Black "Aaron"]
[Result "0-1"]
[WhiteELO "2071"]
[BlackELO "2098"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Bc5
( 4...Nxe4 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Nf5 8.Qxd8+ Kxd8 {is the
classical Berlin.} )
5.c3
5...O-O
( 5...d6 $2 6.d4 Bb6 7.d5 a6 8.Ba4 {and White wins material.})
6.d4 Bb6 7.Re1
7...d6 8.Bxc6 $6
{Since White does not win a pawn on e5 as a result of this trade due
to tactical reasons, this move is premature.}
8...bxc6 9.dxe5 Ng4
{The point. With the double attack on e5 and f2 Black retains material
equality.}
10.Be3
( 10.Rf1 $2 Ba6 )
10...Bxe3 11.fxe3 Nxe5 12.Nxe5 dxe5
{The position is approximately even, assuming White can find a good
square for his knight.}
13.Na3
{This maneuver is a bit slow.}
13...Qh4
{Pressuring e4 and eying the kingside.}
14.Qf3 f5 $5
( 14...Be6 {was safer, but Black plays for more.} )
15.exf5 Bxf5 16.Qxc6
{White accepts the pawn. But now Black gains time to coordinate an attack on
the king.}
16...Be4
( 16...Bd3 $2 17.Qd5+ )
17.Qe6+
( 17.Qc4+ Kh8 18.Qe2 {was a safer alternative.}
)
17...Kh8 18.g3 $2
( 18.Rf1 {and White is alive and kicking. The point of 18.g3 is that
18...Qh3 is impossible. However...
} )
18...Rf2 $1
{Once the initial shock wears off, this move is actually pretty simple
to calculate. The myriad checkmating threats force White to capture
either the rook or the queen (apart from trivial spite moves like
Qc8+/Qe8+/Qg8+/Qh6). But both captures lead to forced mate!}
( 18...Rf2 19.gxh4
( 19.Kxf2 Qxh2+ 20.Kf1 Qg2# )
19...Rg2+ 20.Kf1
( 20.Kh1 Rg3# )
20...Rf8+ 21.Qf7 Rxf7# )
0-1