The 12th version has a few updated lines of theory mostly in obscure lines and such and a few novelties that were used by Super-GMs in Linares, M-Tel Masters, WC and stuff like that-but in reality the difference is too small to affect any player without an IM title.
I used to have fritz 11 now have fritz 12
opening book has changed was wondering if somebody has them both could tell me what the differences are.
All my chess books were very close to fritz 11 is that true of 12?