Help on superstar trigger

Sometimes when i'm with a highflyer superstar, he makes a silly layup which always goes wide, instead of the dunk i wanted him to make.
All i do is press the trigger and shoot or pass or dunk, sometimes it does a great dunk , sometimes a useless layup which goes out.
I'm not standing too far or something, it just does this sometimes.
Anyone else notice this or can help me how to avoid it?

And another thing , how can i set zone defence on keyboard?
It's not one of the 4 plays im allowed during the game, how can i make it one of the 4 in online play because it wont let me in the playbook during the game.

If you're too far away from the hoop when you attempt a Freestyle Superstar dunk, the player will perform a layup/runner instead.