Project 30: What Did I Miss? (3)

In the second game against Dave Baillie, I had this position, as posted yesterday.

Sean Marsh - Dave Baillie

I played 20 Nxd7 but missed the stronger 20 Nxe6!, deflecting the bishop from the defence of c6. After 20 ...Bxe6 21 Rxc6 White would be a sound pawn up and the rest of Black's central pawn structure would have been severely compromised.

The next missed opportunity came against John Garnett in the first round of the Rapidplay event. We ended up playing six games during a very long, tiring and memorable evening: two Rapidplay games in the club championship, two in the Project 30 event and then two five-minute games for the Project 30 tie-breaker.

This position occurred in the first of the Project 30 Rapidplay games.

John Garnett - SM
Black to play

Black is a pawn up and has high expectations of a successful attack on the enemy king. With queen, two rooks and two bishops all pointing the right way, I felt it was time for a sacrifice and I played 23 ...Bxh3! This tears away part of the king's defence and should have opened up the position for a decisive infiltration.

John captured the bishop with 24 gxh3 but I followed up with the incorrect 24 ...Rxf3? after which John repulsed the attack with careful moves: 25 Rxf3 Qxf3 26 Qf2! Qh5 27 Rf1 and even though Black isn't doing badly in terms of material, with three pawns for a piece, I couldn't ever shake John's knight from the weak d5-square and he went on to convert his advantage in fine style.

At the time I felt I must have missed a better attacking option. My intuition told me the sacrifice should be good, but the resulting position clearly lacked a certain something.

Black to play

It turns out I went wrong very quickly after the sacrifice. This is the key position. What did I miss?

Tune in tomorrow for the answer.