Handshake? I like to give my opponents a hug before and after a match!
That gives me a great idea for a move! Right before the match, offer your handshake, say "good luck" and when he shakes, pull his hand up and kiss it like he's the Queen of England. That's get his head all twisted.
Or give him a hug and nuzzle your nose in his neck. Then give him a wink.
How's he gonna shoot straight after that?
But seriously tho, back to 420's OP. If someone shakes my hand weakly, or overpowers it, then it does make me wonder, even if just a bit, about the guy.
Give me a firm shake with eye contact, or I'm thinking I have someone insecure and I just got the first swing of momentum.