Online betting while at game.

This could be an incredibly stupid question but who cares.

Suppose I were at a Red Sox game and Joe Kelly were pitching. If my book had live prop bets on strikeouts, would I be able to load up the prop bet on my phone (or laptop if im hardo and bring it to game) and fire it out right when strike 3 is called? I can't imagine a book being able to close the odds at the exact second I send it in...

Thoughts are appreciated