Two endgames - with two endings

End games are thrilling. One mistake and you have lost it. These two endgames are from GM levels, and illustrates in a complex manner the simple principles involved.

First, a successful for white:

Why does it work? First, black castled on the king side. Second, keeping the pawns defended he was able to attack the knight and queen gaining tempo. Black has no time to rush in his reserves. they just stand there watching the defeat.

In this game, these two factors are dealt with. It is excellent!!