I happened to be discussing the famous Botvinnik-Fischer game with some friends when Angus French pointed out an interesting anomaly at a crucial point.
The anomaly isn't in the game, so much as in Botvinnik's comments on it: at Black's seventeenth move he gave a couple of short variations which he had apparently analysed in his preparation, but which Fischer sidestepped by choosing a third move instead.
Here's the variations given on page 243 of Fischer's My 60 Memorable Games (Faber and Faber, 1972)
and here they are on page 242 of Kasparov's My Great Predecessors, part 2 (Everyman, 2004).
They're two very different extracts purely in terms of text, but in terms of the variations they're almost identical. Both give the line 17...Qf5 18. Qb4 a5 19. Qd4, but whereas Botvinnik as quoted by Fischer gives 17...Qh4 18. Qc2
and then 18...g5 19. Rd4, Botvinnik as quoted by Kasparov gives 17...Qh4 18.Qa3
and then 18...g5 19. Rd4 as before.
So what? They're two different passages (both translations, presumably, but the content is so different that the originals must also be different). But at the same time, both seem to refer to the same thing, i.e. the variations that Botvinnik said he had prepared when previously studying the position. Which makes it a bit strange that one place has 18. Qa3 and the other 18. Qc2.
I did wonder whether it might have been an error in the original 60 Memorable, but the algebraic edition has the same line as its great descriptive predecessor.
So I'm assuming that there's no error in either 60 Memorable or My Great Predecessors and that Botvinnik did give two different lines in two different places.
So from where was Fischer quoting (Chess Life?) and from where was Kasparov? And has the difference been noted previously?
[Thanks to Angus French and Pablo Byrne]