Instead of 17.Qf1 I like 17.Bc4. If 17...Bxc4 18.Nxc4 e4 (say) 19.Qb3 White seems to have a fine game. If instead 17...c6 18.e4 also ensures an easy game for White.

Indeed 17. Bc4 looks stronger and 17. Bf3 is another good option for white. Also on Black's 17th playing for pressure on d4 seems better than the text move, i.e. exd4 followed by Nc6.

White could consider gaining space with 19. e4 and (after 19. .. Bf7) 20. d5. If black then takes on c5 with 20. ... Nxc5 the white rook enters via 21. Rc1.

Perhaps it it is better for white to play b3 so black can't move its bisschop which is followed by Ra1 and the capture of blacks bisschop.

Taking the pawn requires a very fine judgement, as the bishop would be trapped for some time after 21.b3 or 21.Rxf8ch Kxf8 22.b3. But the only way for White to capture it would be to bring the king across, or to manouevre the bishop to c2, then the knight to c3 (as the square most quickly reached). A timely ...a6-a5-a4 would save the B at the cost of a pawn, however.

I prefer 22...Nf6, here, then bringing the rook to d8, operating against the vulnerable d-pawn.

An alternative plan was 25...Nd5 with the idea of 26...Nb4. For instance, 25...Nd5 26.Ne5 Nb4 27.Rd2 Rd6.

Good move. White's oversight is a very easy one to make.

Actually the oversight seems to be black's!! Geert you could have sacrificed your rook here for a winning position: 27. dxc5! Rxd3 28. cxb6 and how is black going to stop the promotion? On 28. ... Rxd2 white has the classical 29. bxc7 and the rook can not prevent c8=Q. So 28. ... Rd8 seems the only defense, but then there follows 29. b7 and the white knight is going to cover b8 in a few moves from d7 or from a6 - black seems helpless.

I think this was a serious blunder from your opponent; after 28... Nxb3 29. Rxb3 Rc4 she will win your c6 pawn unless you trade rooks, i.e. 30. Rc3 (30. Ra3?! a5) Rxc3 31. bxc3 a5 and black has a won endgame because of his passed a pawn and your doubled pawns.

The move played turns out to be fine, but 28...Nxb3 is simplest and best. Black also had the intriguing possibility of 28...Rd3. If then 29.Rxd3 Nxd3, Black wins the b-pawn. But the line is a little more complicated than that: 30.Nd4 Nxb2 31.Ne6 Nc4 32.Nxc7 Ne5 33.Nxa6 Nxc6 and Black ought probably to win this ending. Otherwise 29.Re8ch loses the exchange: 29...Kf7 30.Nxc5 Rd1ch etc.

Not so good now the WK is closer to the centre. Better is to reprise an idea already mentioned: 29...Nxb3 30.Rxb3 Rc1. The remote passed pawn that results from rook exchanges, or the two extra pawns Black has if White keeps the rooks on, ensures Black a big advantage. A possible line is: 29...Nxb3 30.Rxb3 Rc1 31.Ra3 Rxc6 32.Rxa6 Rc2ch 33.Kf3 Rxb2 etc.

After exchanges, White's king is much closer to the centre, and will pick up the front c-pawn. After that it's very difficult to assess chances.

What if white attacked the black rook with 31. Ke1, it would give him a tempo to save his hanging knight... but it does cost a few pawns...

I rather think I'd prefer 35...Ke5, here, confining the WK to the Q-side. After the text move, Black could play 36.Kd5, diving into e6-d7xc7 if the BK advances.

Indeed, Ke5 is accurate and might lead to a free pawn for black on the c-file.