woldsmandriffield: 
click for larger viewA very instructive R+P ending that might be shown to any juniors you are training. Karpov captured 76..Rxf2+ and now Olaffson played 77 Kg3! If White had gone 77 Kg1? here 77..e3 wins after 74 Rg8 Rf7 and now:
a) 75 Re8 Rg7+ (not the tempting 75..Kf3? 76 Kf1 escaping with a draw) 76 Kh2 Kf2 77 Rf8+ Ke1)
b) 75 Kg2 Rd7 76 Rg6 (76 Re8 Rg7+ wins as above) 76..Kd2 77 Ra6 e2 (77..Rg7+? is no longer a win because Black has 78 Kf3 Rf7+ 79 Kg2 and if 79..e2 80 Ra2+ draws since the Rf7 is misplaced) 78 Ra2+ Ke3 79 Ra3+ Rd3
c) 75 Rg6 Ke1 76 Kg2 e2 77 Ra6 Re7
After the correct 77 Kg3! Karpov checked with 77..Rf3+ (77..e3 is answered by 78 Ra4 Kd1 79 Ra1+) 78 Kg2 Ke3 (78..e3 78 Ra4 Rf2+ 79 Kg3! as before) 79 Rg8 (the Rook gains more freedom for action) 79..Rf2+ (79..Kd3 80 Ra8 with checks from the long-side of the pawn to follow) and now Olafsson again made the right choice: 
click for larger view80 Kg1! ...
This time 80 Kg3? would lose to 80..Rf7 with similar variations to the note to 77 Kg1? 80 ...Rf7 81 Ra8 Rd7 82 Kf1 Rd1+ 83 Kg2 Ke2 84 Ra2+ Rd2 85 Ra1! (since the pawn has not yet gained the 6th rank 85 Ra3 also drew here but Olaffson plays the principled move: when as defender your King is on the short side of a passed centre pawn, play the Rook to the 8th rank) 85..e3
click for larger view86 Kg3! ...
Again, the principled move. any Rook move between a4 & a8 also draws. A good question to ask a junior is why 86 Ra3? loses here. The reason is Karpov has a sneaky discovered check: 86..Ke1+! That's also why Olafsson's 86 Kg3 is the best move in this position. 86..Rb2 87 Kg2 Kd3+ (not dangerous) 88 Kf1 Kd2 89 Kg2 Ke2 (89..e2 90 Kf2) 90 Kg3! Rd2 91 Kg2 Rd1 92 Ra2+ Kd3 (92..Ke1 93 Kf3 wins the pawn) 93 Ra3+! ...
The last opportunity to go wrong 93 Kf3? is a bad move losing to 93..Rf1+ 94 Kg2 e2) 93..Ke4 94 Ra4+ Rd4 95 Ra8
and here Karpov agreed a draw. After 95..Rd5 96 Kf1 Rd1+ 97 Ke2 the pawn is lost (or if Black is very careless the Rook!). | 
Kibitzing
