The coach moves the black bishop to e7 to prevent a pin from my white bishop.But can't he just push his pawn on h7 to counter attack instead of putting his bishop there? I don't see any utility right away. It might be development perhaps but I'm still confused!
Turns out that the immediate ...h7 is a big mistake. Black will end up losing a pawn or sacrificing his pawn structure.
That is crazy! How can I see this type of bad move and prevent myself from doing it?
I couldn't see the outcome like you did
That is crazy! How can I see this type of bad move and prevent myself from doing it? I couldn't see the outcome like you did
There is no easy answer. Simply, keep playing and studying. And use the Chess.com tools and engines to look at mistakes. There is no "shortcut" to get better other than putting in the time! 
Good forum topic and @Alramech gave some good analysis
Even if this ...h6 move didn't lose a pawn (like this case does), it is still usually a positional error to advance pawns in front of your castled King. Here is an earlier video from my channel (before I got a webcam) on why pawns shouldn't be pushed in front of your castled King usually:
For a more recent video of mine where the ...h6 move (in a different opening) ran into more positional trouble, then here is a good example of this:
Hey! I'm very new to chess and I am trying to learn the basics!
I just discovered the queens gambit but I have a question that is not necessarily linked to it but I see this situation in a lot of my games.
The coach moves the black bishop to e7 to prevent a pin from my white bishop.
But can't he just push his pawn on h7 to counter attack instead of putting his bishop there? I don't see any utility right away. It might be development perhaps but I'm still confused!