I think the key is body punches. Who can land more effectively to the body is my big factor.
And the other important thing is how Cotto will fight. Will he fight in retreat or will he stand in front of Clottey.
And will Clottey use movement which he's shown he can do.
Very interesting match up. And I hope Cotto is focused on this fight instead of a possible bout with Pacquiao.
The biggest factor in Cotto/Clottey is Confidence
Clottey has shown to lose focus and drive when faced with tough challenges. He did this with Margarito and also showed some of this against Zab.
Cotto got the Puerto Rican beat out of him by Margo. You can't say he wasn't doubting himself up until the fight with the Brit. He showed this when he celebrated the ending of the second round after he downed him from body shots (I think it was the second).
Both fighters have the tools to beat each other. It will mostly depend on who will be focused and confident in their abilities.