This attempt to plug the dark squares fails, because the white king is too open.

White resigned, because of 30.Kg3 Rg2+ 31.Kf4 Rf8+.

White is extremely cramped, with his biggest problem being his knights – one is stuck on the edge of the board and has no moves at all, and the other is restricted to the first two ranks. Even so, the position is very closed, so it is not so easy to realise Black’s advantage. One possible plan is to put a rook on b8, transfer the bishop to c7 and the queen to d8, thus attacking the Na5. In reply, White would probably have to put his queen on a3, and then Black could take on a5, and try to arrange ...b5-b4. But this all takes a long time, and such a plan needs to be implemented very carefully. Instead, Black realised that the white pieces are so uncoordinated that Black can permit himself a positional piece sacrifice:

More tenacious was 33.Kd2, after which there could follow 33...Bg6, followed by ...Rb6-e6 and ...Bg7-f6, preparing pressure on the pawn at e3.

Despite his extra piece, White is helpless – his pieces have no squares, and Black is organising pressure down the e-file.

White resigned.

A simple but effective tactical blow – the black centre immediately collapses.
The decision taken is much more pragmatic than the move 16.h4!?±, which requires much more calculation.

Very inaccurate was 17.f4? Be6 18.fxe5 f4!, with practical compensation.

After 17...Nxe5 18.Nc4 Qe6 19.f4± Black is simply a pawn down.