You have a friend with whom you play regularly. You want to help each other get better, and you frequently discuss strategy, hands, etc. You've picked up on a tell of his.
Do you ...
- Tell him about it?
- Keep it to yourself and exploit it?
- Let him know you have something on him, and then beat him mercilessly with it until he figures it out?
- Something else?
To further complicate things, imagine this friend (whom you do want to see succeed--just not against you) is entering a major event soon. Would you give up this edge you could have on him?