OK, look: The third-base coach has a lot of responsibility. He relays signs from the manager to the batter and base-runners, and he actually participates in on-field action in a way no other coach does — by judging whether a base-runner should try to advance or stay put.

The first-base coach has significantly less responsibility. Presumably it varies from club to club, but in terms of meaningful communication and decisions, he’s just charged with way, way less than his counterpart across the diamond. The first base coach there to congratulate any runner who reaches first base safely, and to collect any batting gear the player does not want weighing him down on the basepaths — elbow pads, shin guards, that little thumb-ring thing they have, even batting gloves if the guy likes to run the bases au natural.

But the main thing the first-base coach absolutely needs to be doing whenever there’s a runner on first is paying attention to the pitcher’s pickoff move and, when applicable, yelling “BACK!” to let the baserunner know it’s coming.

All that adds up to make this one of the most brutal retributions for poor first-base coaching I have ever seen. Let it serve as a lesson to first-base coaches everywhere: Never, ever sleep on a pitcher’s pickoff throw.

The video was uploaded to the Internet in May, 2012 by a Youtube channel that aggregates user-submitted videos. Based on the front and back of the first baseman’s uniform, it seems likely he’s Diamondbacks farmhand Tyler Bream. But the pitcher’s last name is Valdez, and Bream has not had a teammate by that name in either of his regular-season stops — meaning this is likely an instructional league or minor league spring training game. So there’s some chance the first-base coach in question is a young player doing double-duty, but anyone who knows more than that is welcome to send me an email. And if you’re the unfortunate first-base coach in question, I’m sorry. Very, very sorry.

(Thanks to Diamondbacks reliever Brad Ziegler for calling this to our attention.)