If Hearns had a solid chin like Duran, could Hearns have beat Hagler?

Yes! he could. He made Marvin's face full of blood in round 1 so if that fiight had gone to the distance and Hearns had a chin like Duran, Hearns could have made that cut on Marvin face become worse and worse and the fight could have been stopped. It's just like Lennox stopped Vitali by way of TKO in round 6.

 

Eddie Hearns has got a good chin but I doubt he beats Durans

 

Skinny dudes rarely have solid chins.
Hearns legs were skinny so he didn't have a solid base to hold him up when he'd get stunned by a good shot.

Its that skinny body that made Hearns have the height and reach advantage that he had, and gave him a lot of the physical advantages along with that like quickness and speed.
…...so if Hearns had a thicker neck and stronger legs to have that better chin, other parts of his game would suffer that he would need to beat an atg like Hagler.

 

Chin had nothing to do with Hearn's defeat: he lost because he fractured his right hand 30 sec into the fight, right after hurting Hagler with it, and then couldn't hold him off with only a good punching left hand.

Hagler was known for dipping his head on incoming punches to inflict damage to the knuckles.

He did the same to Duran.

This could easily have been a defeat, because he was getting lighted up on the inside with regularity.

 

If Hearns had boxed instead of going full throttle, he could have won against Hagler.

 

Hearns lost that fight because he was reckless. He made for a great memorable fight, but he left himself open to the punches when he didn't have to. But had he not done that we would have had the great Hagler vs. Hearns, and that is more important that who won at this point now 33 years later. Had Hearns or Hagler won a boring decision with Hearns boxing it would not have been remembered the same way.. That fight helped the whole fab 4 bunch because it defined them as warriors.

 

Even if Duran lent Tommy his chin I'd favour Hagler. He was that good.