This is the sort of thing that ordinary players are not good at seeing -- the relative values of pieces in various endings. Some might believe that the bishop is OK here, with pawns on both sides of the board. But White maneuvers the Knight brilliantly.

It would be good to see fewer posts about who woulda coulda shoulda beaten who when why. These questions have no answers, and have very little to do with chess.

1. Black wanted to protect his f6 pawn temporarily so black chose 54...Ke7 (which is the right move).

2. If 54..Bxf3 then 55.Kxf6...white king at f6 would be very strong due to different colored square with the opponent bishop then after that white knight would prowling around and perch at f5 square deny the d6 square for black king. If bishop exchange the knight then white would win the pawns vs pawns ending.

3.Why so in rush to take f3 pawn....experienced player knows that after 55.Nxd5 black king could always harass the white knight just until then the f3 pawn could be taken. So It could be delayed!!

After his defeats in the early part of the match, the opening seemed to fall off the map; moreover, it have been a case of fashion in any event. Inter alia, I was witness to this game (K Spraggett vs B Ivanovic, 1984), when the opening was getting played to death.

Three rounds on, in the final round at Toronto, I faced Deen Hergott and played the old Tarrasch Gambit with 9.dxc5 d4, because I had no desire to play twenty-plus moves of theory. Got what I thought was a decent game, then Hergott sacrificed an exchange for tons of play, and the remainder did not last overlong.

<....The Karpov of 1984 seemed to be able to drain the energy out of black's initiative, making the opening itself look suspect....>

Round about this time, P C Griffiths and John Nunn co-authored Secrets of Grandmaster Play, in which Griffiths discussed Nunn's adoption of the Tarrasch, a favourite in the late 1970s. Griffiths wrote, in his annotations to J Nikolac vs Nunn, 1979, that Black's winning chances were not wonderful at intenational level, as White could play with less than 100% accuracy and still hold the draw.

<....But there have been many good Tarrasch games since then: Kramnik-Illescas springs to mind.>

Is Kramnik vs Illescas Cordoba, 1993 the game you mean?

click for larger view

How many players without an adjournment would agree a draw here? And how many could find a way for white to pile on the pressure from this position?

IMO Karpov would have won even more games in his career without the adjournment. His practical play in this phase of the game was stronger than most.