Black to move. How can Black save this game? 
Chess Daily News from Susan Polgar
Endgame saving technique
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Black to move. How can Black save this game?
a5!
1… a5! 2. Kd4 a4 3. Kc4 Ke6 4. c6 bxc6 5. bxc6 Kd6 6. Kb4
Kxc6 7. Kxa4 1/2-1/2
After 1. …a5, the key move is 3. …Ke6. Pushing the a-pawn on move 3 loses!
– Mike D.