Ray Vecchio, Benton Fraser and others in “Diefenbaker's Day Off”

Okay, so how do you know the guy who paid Charlie's a fighter?

His wrists. They were completely hairless, indicating he wears gloves that are tied tightly in a constant use.

So we're tracking a guy with hairless wrists.

Also, the second knuckle of each hand is slightly lower than the others. His jaw clicked slightly when he spoke, indicating a fractured mandible. And his eyes had shifted downward and laterally in their sockets, cause, no doubt, by repeated blows to the zygomatic arch.

Okay, that I'll buy. But how'd you know he worked out in this gym?

It was written on his t-shirt.

You couldn't have said that in the first place? You had to go through the hairless wrists and the fractured mandibles?!

I'm sorry, Ray.

Aw, man!