21.Rxd8, though White should eschew any ambitions involving Black's c-pawn: 21.Rxd8 Qxd8 22.Qxc6? Qd2 23.h3 ... (23.g3 would be bad, after 23...e4 24.Bg2 Qe1ch 25.Bf1 Bd3) 23...e4 24.Bg4 Qe1ch! 25.Kh2 Qxf2! (NOT ...f5 as the White Q draws by checking on the dark squares) 26.Qd5 ... (Black threatens to run the e-pawn home) 26...f5, trapping the bishop. No perpetual being possible, Black wins).

Fritz agrees with the Archduke.

21...e4 would have been playable here, as after 22.Bxe4?? Qf4 wins for Black.

I see why, as a checkmate threat on f2 would be very difficult to drive off, and white's K would wind up exposed.

Fritz likes e4

Fritz likes this move.

I think Black is right to keep the queens on. The end game without them looks fairly drawish. But maybe 22...Qe7 23.Re1 f5 might have been an improvement.

I also reckon that black's instincts were correct.

Fritz considered various queen moves, including this one, but eventually settled on 22....Qd8

I would think 23...Qb6 where mate is threatened.

Fritz wants to play 23. h3

So... NOT ...Qxa4, then?

I found the move. But, there was more then I realized. As I thought that there was just a little bit of pressure for white which made it difficult. But, it was more then I realize since ...Bd3 wins the Q, as white must give it up to avoid checkmate.

Fritz prefers the simple capture on a4.

Oops... Possibly White couldn't face 24.Qf1.

I think that it's a move that your discussed above being 24...Bd3 which puts the B under pressure. It would appear to white must lose a piece to protect his Q and avoid checkmate.

Fritz likes 24. Qf1 with advantage to black.

Crushing. White has no real choice. White's game was no doubt difficult, and gradually being driven into a passive position, but material was still level, and, after 24.Qf1, not easy for Black to break down, even were he to win a pawn somewhere.

Yes I did. I knew that he couldn't capture which means that a piece is gone.

And the game is more or less over, so I am ending computer analysis here.

I would've just retreated the Q to prevent that, as it's not mate right afterwards. Yes, white is down a B, but it's better then the Q which is about to happen.

Actually I think it is worse to go a whole bishop down, rather than rook and bishop for queen and pawn.

Makes it more difficult for him.

So he is driven into a passive position, anyway.

Interesting for Black - a thankless task for White. If pawns were level, White could make a serious fight for it. A pawn down as well as Q for R and B - too tall a mountain to climb, methinks.

I think so to.

Yep: the e-pawn is the 'candidate', running for royal office...

I still would have played ...f5 here, with the follow-up plan of ...g5, ...f4 etc. There is nothing wrong with the Queen move, though.

Which I think you'll achieve.

30... e3 might have been better but the text is still good.

I still like 30...f5. But 30...e3 is decisive: 31.fxe3 Qxe3ch 32.Kf1 ... (forced) 32...Qe4! 33.Re1 Qh1ch 34.Kf2 Qxh2ch and the 3-1 K-side majority wins the game.

Yes I missed a quicker win here.