Looking over this game between Tal & Botvinnik, 1960, Moscow, Game 1, on Fritz9, I wondered if this could be a rare gross blunder by Botvinnik. I have the book on the match but I haven't consulted the analysis found there. The Fritz engine did not suggest Botvinnik's next move, preferring 29...Kb7 or 29...Kb8, evaluating the position as +- 2.58 for white. I was quite surprised to see Botvinnik allow Tal to skewer him after he played 29...dc4 30. Bc4 Qg7 31. Bg8 Qg8 32. h5 1-0