Courtesy of flipflopflyball:
And as far as I'm concerned, this is a nonissue. Dallas Braden did the right thing by defending his mound. Alex Rodriguez did the right thing by skipping through the pitcher's mound if he thought it would rattle Braden.
I don't know whether it's an "unwritten rule" or not that batters avoid going over the mound ... but whether it is or not is not the issue. These are world-class athletes performing under levels of stress we can't even begin to imagine. If A-Rod thinks it'll help his team win, and he is willing to face the repercussions, then by all means he should do it. It actually speaks volumes about his character that he cares more about winning than what the opposition thinks about his actions -- that he might be willing to take a heater in the ribs the next time up for the sake of rattling Braden. Good for him. And good for Braden for having some personal pride and letting A-Rod know that he noticed.