Annotated chess game

At this point I was thinking it was all over and for all intents and purposes it was over really. My position was in tatters now. Snowman.

Dr Siegbert Tarrasch has this to say about this sort of thing: "Once get your knight firmly established at King's Sixth, and you may go to sleep. The game will play itself." An exaggeration, of course, but a pointed one. Black has no convenient method of evicting that knight, neither.

Yes I thought it absolutely imperative for survival to kick the knight out. Snowman.

Yes. Computer says Q x B here..Obviously I didn't spot that move for White but luckily neither did White at the time.

Creative, and shows flexibility of mind. Just a miscalculation: 18.Qxf4 exf4 19.exd7ch Kxd7 20.Bd4 etc whereat Black falls a rook behind. Or 18.Qxf4 Qe7 19.Qf7ch Qxf7 20.exf7ch Kxf7 21.Bxb7 Rb8 22.Bd5ch Kg7 23.Ba7 and White remains a whole piece ahead, and with the bishop pair as well.

Yes I was also thinking Rb8 if the Bishop captured on B7 but failed to spot the next move of Bxa7 so good job it didn't go that way. Snowman.

...Rb8 might have been bad. I'd have followed with Bc6+ with check and then capture the rook the next move. That was my original plan, which I passed on thinking I could pick up TWO pawns (and also thinking you'd have spotted the risk to the rook, which you may have had it gone that way).

In my view there is little to choose between the two. I'd probably opt for this: 19.Bxb7 Rd8 20.Bc6ch Kf8 21.g3 Bh6 22.Bxa7, but the similar line beginning 19.Qxb7 is probably as good.

This is fine. It can transpose into the sort of attack I had in mind when looking at this position.

I think it's because of Rg1 pinning the Queen against the Bishop and I couldn't defend both the Bishop on g5 and the Rook on c8. Snowman

oh, right. that's probably it. in addition to picking up the black rook, the white queen might become a serious threat if you recaptured the white rook.

Strictly speaking, the situation after 22.g4 Qxg4 23.Rdg1 ... is the reverse of a pin: a 'skewer'. The heavy piece pretty much has to move (in contrast to the pinned piece, which dare not), uncovering the undefended man behind. But the move played seems to me reasonable, as does 22.Bxa7.

Perhaps 23.Be3 might have been a more effective exploitation of the masked battery on the f-file? The idea is 23.Be3!? Qg4 24.Bxg5 Qxg5 26.Bf7ch ... Now if 26...Kf8 or ...Kd8, 27.Bd6 wins the exchange. But instead 26...Kd7 meets with a different fate: 27.Rxd6ch! Kxd6 28.Rd1ch Nd5 29.Qxd5ch Ke7 30.Qe6ch Kf8 31.Qxc8ch Kg7 32.Qxc7 and wins. There doesn't seem to be much option: 23.Be3 Qg4 24.Bxg5 Nxd5 25.Qxd5 Qxg5 26.Qe6ch Qd7 27.Qxc8ch wins a rook (Note that 26...Kd8 27.Rf7 and mates quickly).