The power of a pawn avalanche

Please look at following position:

Black has given a knight for 3 pawns . This looks good if black can manage to bring the both ones on fifth row forward.

But there is a danger. White is threating Nc4+ Nxb6 + Rxf2. If he would succeed with that plan his worries would have become smaller.

So black went for a resolute solution of that problem:

The power ofa pawn avalanche you can also see in the following game:

 4 pawns for a rook

Later they reached following endgame. Enjoy the fight!

a) The pawn avalanche comes up -

b) 3 pawns against the rook -

c) White defends well-

d) Under pressure white fails and the pawn avalanche triumphs: