I didn't understand how the win decision got to L.Vizcaino on 07/21. Can someone explain it to me?

This is one that is left to the judgment of the official scorer. Normally, the pitcher that is in the game when his team takes the lead for good gets the win. That would have been DeSalvo, but there is a rule that a starter must go at least five innings to get the win. So the official scorer can give the win to the relief pitcher who was the "most effective".

Let's look at the other NY pitchers: Bruney allowed two hits and a run in less than an inning. Myers faced only one batter. Villone pitched the last 2 innings and allowed a couple hits.

Viscaino pitched 1 1/3 innings, allowing no hits and no walks. So in the scorer's judgment, he was the "most effective" of the NY relievers, and therefore gets the win.

This is a judgement call for the official score keeper. DeSalvo did not pitch 5 inn., so he is excluded. The score keeper chose Viz as the most effective pitcher after that.

PS: WP stands for wild pitch

Viz got a win last week and only threw 1 pitch.

Nacnud has it right.

All I would add it that the score keeper may have decided that Vizcaino was the first effective pitcher rather than the most. It is his judgment.

desalvo shood have gotten the win because the yankees were ahead the entire game from start to finish

They made a mistake. Bruney got the win. Under the pitching stats it says "WP-Bruney"