I can understand why I score badly when I am tricked into opening variations that I don't like and have not prepared. It's more surprising when the same happens in my favorite variations.
As far back as I can remember I have had a weak spot for the Kan variation: 1.e4 c5 2.Nf3 e6 3.d4 cxd4 4.Nxd4 a6!? Or actually for three sub-variations that can arise from it:
a) 4.Nc3 b5 5.Bd3 Bb7
b) 4.Bd3 Bc5 5.Nb3 Ba7
c) 4.c4 Nf6 5.Nc3 Bb4
I cannot recall exactly when I first saw saw these variations but they must have been among of the first Sicilian variations I came across.
Unfortunately these very variations seem to be weak spots in my chess understanding. I have played them in a few tournament games with catastrophic results and my blitz results have not given me any reason to give them a new chance.
I cannot say exactly why my score is so miserable. It's hardly the variations' fault as they according to MegaBase 2008 score very well for Black. It more likely is due to the fact that those bishops in the long diagonals - normally pointing towards White's king - tempt me to play for a king's attack with moves like ...h5 and ...Nf6-g4 when patient consolidation and queenside play are called for.
Maybe some day I will find the time to write a repertoire book based on these lines - just for myself. In the meantime I will start posting a few annotated games here.