Over 15 Marvin would fade badly and Pac just might be able to KO Hagler. He's not as marvelous as some people say :deal
Now that I think of it, he did beat a prime DLH, Cotto, and the always dangerous Ricky Hatton... So **** Yea!!
Hagler might see the final bell over twelve. Hell, Cotto almost did. Over fifteen? Pacquiao catches him late. Pacquiao always ends the fights with full wind in his sails, whereas Hagler is known to lose the Championship Rounds. Against Pacquiao that means getting caught big.