Angelo Dundee knew how to talk tough with his clients. He told Sugar Ray Leonard late in a big fight, "You're blowin' it, kid, you're blowin' it!"

And he knew when to soft-pedal the advice, as with a young Cassius Clay:

“I never touched that natural stuff with him,” Dundee said in his memoir: "So every now and then I’d subtly suggest some move or other to him, couching it as if it were something he was already doing. I’d say something like: ‘You’re getting that jab down real good. You’re bending your knees now and you’re putting a lot of snap into it.’ Now, he had never thrown a jab, but it was a way of letting him think it was his idea, his innovation.”  

What was the secret to being a trainer? Not needing to be the star, Dundee said—but knowing how to be everything to the star: “You’ve got to combine certain qualities belonging to a doctor, an engineer, a psychologist and sometimes an actor, in addition to knowing your specific art well. There are more sides to being a trainer than those found on a Rubik’s Cube.”

Sounds like the best communicators I've known.