Advanced chess tactics

The art of winning a won position.

You have an attack and you need to bring back the full point. How many times missing the key moves cost 1/2 or even a full point ?

Lets practice to collect rating points later on . These are advanced chess tactics and puzzles, needing calculation. Not your puzzle rush 1 to 30 run.

Position 1: White to play and win 

lets move to a slightly more difficult position, where Black seems to have things "under control" at first sight. look closer !

Position 2: White to play and win 

and finally a sharp position with several candidate moves, maybe the solution is not unique unlike puzzle rush problems. What would you play here ?

Position 3: White to play and win 

Please post your solutions in the comment section.