Fuck it, it's Marlins Day. The Marlins have the third-smallest stadium capacity in baseball, and that's still way too large for the anemic crowds they've been drawing. So they're going to shut down the entire upper deck for certain weeknight games. This, according to a team spokesman, "will give an overall better fan experience." Who likes math? Marlins Park holds 37,442. Average announced attendance, through 16 home dates, is 18,864. (That's the number of tickets sold and otherwise distributed. The actual number of people in the park, judging from the difference between last year's "announced" and "turnstile" attendances, might be somewhere in the neighborhood of 10,000.) There's really no reason that few people deserv…