http://en.wikipedia.org/wiki/World_C...mpionship_1984
Look at the note at the bottom of the page above the citations...
Crucial game 16
One move in game 16 may have had a profound effect on chess history. In this position, Karpov was tired and offered a draw (and Kasparov accepted) (Kasparov 2008:137–38). Karpov should have won if he had played 37... Rd5! At this point Karpov was leading the match 4-0. If he had won this game, his win in game 27 would have ended the match with a 6-0 victory.
While on...
http://www.chessgames.com/perl/chessgame?gid=1067138
The Queen is on a different square in the end position. I would say that's pretty important since there's a claim that Karpov could've won here with a skewer on the Queen and Knight.
What's going on here?