Chess is not always a simple game

Strong players make it all look simple, but, at least for the rest of us, chess is anything but simple.

Wall,B - Guest344942
Playchess.com, 2013

1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+ 

4...Kxf7 5.Nxe5+ Nxe5 6.d4 Bxd4 7.Qxd4 d6

8.Qd5+ Kf8 9.0-0 Nf6 10.Qd4 Nc6 11.Qd3 Qe7 12.Nc3 h6 13.Bf4

Chess is not always a simple game. Black, with a piece for a pawn, must be better, but he still has to complete his development and get his King to safety, while White has already connected his Rooks.

Black's plan for castling-by-hand will give his opponent a target.

13...g5 14.Be3 Kg7 15.f4 Ng4 

Black figures that he has time to trade off White's Bishop. For some reason he abandons that notion a couple of moves later, to his detriment.

16.Nd5 Qd8 17.Bd4+ Kh7

An unnecessary flinch. Necessary was 17...Nxd4 18.Qxd4+ Kh7 19.fxg5 (threatening 20.Rf7+) when White has nearly equalized, e.g. 19...Ne5 20.gxh6 Qg5 21.h4 (bumping the Queen off the g-file) Qxh6 22.Nxc7 Rb8 23.Nb5.

Now the roof falls in.

18.e5+ Kg8

The only escape from mate was 18...Kg7, although then there is 19.e6+ Nxd4 20.Qxd4+ Kg8 21.e7 Qe8 and 22.fxg5, threatening 23.Rf8+.

19.Qg6+ Kf8 20.fxg5+ Black resigned