Joe Nathan’s pine tar

When I wrote the K-Rod post (and follow-ups), many people wrote in to offer other pitchers I should look at, and Joe Nathan came up a lot. So skip ahead a few weeks, and right now I’m watching him pitch against the Mariners — and there’s pine tar on his cap. I saw it a lot heavier in some of the evidence readers sent in, but there’s a light-brown patch on his brim that’s almost the exact same size of the four fingers of his hand.

It’s not resin. Even if you want to argue that whatever was under K-Rod’s cap was a wacky localized migration from the rosin bag, here’s a pitcher with something that couldn’t possibly get there without his knowledge (unless you want to argue that someone else regularly puts pine tar on his hat and he doesn’t notice).

Interestingly, though, while I’ve seen the pine tar much heavier and I’ve seen him directly rub pine tar spots while getting ready, tonight I didn’t see him touch that pine-tar smear at all — but he went to the back of the cap with his hand repeatedly, including a couple rubs. Unfortunately, watching on TV you don’t get good close-ups of the back of his cap, but it didn’t look like there was something there.

All of which raises a different set of questions for me —
If Nathan didn’t go to the pine tar to get a better grip, why risk going out there like that, unless (as we saw with K-Rod) pitchers having illegal personal stashes of sticky substances on their uniform goes unenforced?

If he’s not using it to get a better grip on a cold, damp night - when he went out there, it was about 44 degrees, 82% humidity, raining very lightly - when would he use it? Or is it not about grip at all?