About what percentage is mental?

[flash277]

MN, the best Yogi quote ever was when he got pizza:

Do you want that cut into 4 or 8 pieces Mr Berra?

You better do 4, I couldn't eat 8 pieces.

Yogi also said "I can't think and hit at the same time"

 

[uncdrew]

As a pitcher's parent, it's always a bit nerve-wracking to witness the first home run hit off them. Or the first hit batter.

Do they get upset? How does that manifest? Do they cry? Do they fall apart? Do they bear down and get tougher?