So, my wife who knows that you don't use a football in a basketball game at the world series....says that's a Rally Hat.
"He may have been using it as a rally hat. In baseball, fans turn their hats backward to indicate their enthusiasm that their team, although behind, can come back and win!"
When I pointed out the others in the photo do not have their hat on backwards, she pointed out:
"But the other people have hats of a different color J Their team is ahead. J Ya gotta shield your eyes from the sun if you’re wearing a rally hat!"
So, you go blind and sunburn the snot out of your face to support your losers...err...team.