Fritz prefers 21. Bb5.

I hadn't considered any alternatives to the immediate recapture, but now would have been a good moment to do so, as the d-pawn was half-pinned.

I prefer 24.Bd3, here - so much so I probably would have played it without a thought. That would have stopped 24...Nf3 just as effectively as then 25.h3 h6 26.Be4 would have won a pawn. Instead he would have played 24...f5.

After 24. Bd3 f5 I thought my bishop had few prospects and he has played a move (f5) that I don't really want him to play, but Fritz likes 24. Bd3.

Normally one would avoid playing a move like this, because b2-b4 in response would tend to lame the majority. But that doesn't hold, here, as the BK, in close attendance, would permit ...c5, immediately progressing his majority.

Mobilising his majority. Maybe this should have waited a move in order to throw a spanner in White's K-side machinery: 25...f5!?

26.g4 would have got the White majority rolling. Not that there is much in it really. The game is looking to be 'too close to call' right now.

Fritz prefers 26. g4.

It was a toss-up between this and 27.b3 In think. The direct defence makes it difficult for Black to progress on the Q-side; this counter-attack forces Black himself to look to defence.

Fritz likes 27. g4.

30.Kf5 was one of those moves worth considering, but very, very cagily. In fact it would (probably) have lost: 30.Kf5? b4 31.Bf3 ... (Not Kxf6 as ...c3 rushes a pawn through) 31...a4 32.Bd1 b3! (IT HAS to be this pawn) 33.axb3 axb3 34.Kxf6 Nd3 (this is getting exciting) 35.f5 Nxb2 36.Kg7 Nxd1 37.f6 b2(...Kd5 might be better. Both sides will Queen, and the BK might be better off closer to the rest of his army) 38.f7 b1=Q 39.f8=Qch Kd5. Has White enough checks to hold the draw, or can the King escape within his own army? What is clear is that after 30.Kf5, White's chances of holding the game look problematical at best.

Playing for an elusive (or is it 'illusive'?) win...   I think he ought to have taken the draw by 30...Ne6ch.