Another count against statistically analysing SAN strings to death is some of the rules of that format. There's a lot of weight given to disambiguation in this

Another count against statistically analysing SAN strings to death is some of the rules of that format. There's a lot of weight given to disambiguation in this video. In SAN you must not (if you're following the rules, some software including ChessBase doesn't follow the rules) disambiguate if one of the pieces is pinned to the king. So 1.d4 e6 2.c4 Bb4+ 3.Nbd2 Nf6 4.Nf3. Not 4.Ngf3. This muddies the waters I think, these doubly disambiguated moves he lovingly isolated would be recorded differently if a marginally involved piece was pinned. More significantly, there's no SAN notation for stalemate, or en-passant (or many other things of course) of great chess significance, perhaps more worthy of analysis. The video was still a great technical achievement, and very entertaining for a chess nerd like myself.