Lesa Lessons III

MY round-three game quickly reached the following position in an Exchange Variation of the Spanish.

Black has just played 13...h5 in Spanton (1937) - Francesco Liloni (2165)

*****

*****

*****

*****

*****

*****

*****

*****

The main theme of this variation is the battle between White's superior pawn-structure and Black's bishop-pair.

Accordingly I played 14.Bg5?, apparently semi-pinning the black knight (it can get out of the pin with, for example, ...Nd5, but that allows an exchange of bishops). I had seen that 14...Nxe4+?? is a blunder, thanks to 15.Nxe4, but missed 14...Ng4+!, after which White's kingside structure is compromised, and Black has the only long-range pieces capable of acting on diagonals.

LESSON: check those checks.