How can I convince him to say yes?

[Domino]

I liked this guy for 2 years. We are on the swim team together. Well I asked him out and he asked for a few days to think about out it and i still don't have an answer. I know he's still thinking about it. How can I convince him to say yes and believe I'm the one? Help me plz. Thx
-Domino

[RyceCube]

Odds are if he needs a few days to think about it, convincing him to say yes isn't going to be the gratification you really want.

If you are hard set on trying to convince someone to do something they are unsure about then you can always confront them with utmost confidence like a "sales" person and explain to him that you are only on the market for a short time, you got other guys lined up. "I'm choosing you and the window I'm available is closing."

Think of the ways you can benefit him too. Reputation wise, swim team advantages, social atmosphere, etc.

I don't agree with doing this, but it will help you with your question.