Apollo Creed vs Rocky Balboa. Boxer Puncher vs Boxer Slugger.

Assuming we're talking in their prime here, there's no doubt about
Robinson's boxing ability, but most people underestimate the brutal
force of Hagler and his ability to take a punch, even one as hard as
Robinson's. It'd be interesting to see how Robinson handled Hagler's
unorthodox southpaw style.

I love Robinson, but still think that Hagler would win, though not by a
KO. I'll take Hagler in 15...using your cash.

What can I say...I'm a homer.

I apologize for making this review so long:
Robinson would have chewed him up and spit his ass out in the 1st round.

Update: Seems to be some need to provide rationale for my contention, not that Robinson would win, but that this one would not be close.
Anyone who even casually follows boxing knows that Sugar Ray Robinson is the consensus pound-for-pound greatest of all time. It is more than just Robinson's record (173 wins in 200 fights, 108 by KO) however that earned him this special place in boxing history. A short list of his victories: Jake LaMotta, Carmen Basilio, Gene Fullmer, Carl 'Bobo' Olson, Henry Armstrong, Rocky Graziano and Kid Gavilan. Those are impressive victories over some fighters who are also considered top-tier in boxing history.
Now let's talk Hagler. Was he a good fighter, a good champion for his time? Yes. But what "legends"...what greats did he fight and defeat? His three most famous fights were vs. Duran, Hearns, and Sugar Ray Leonard. All three came up in weight to fight Hagler on his turf. I personally saw the Duran fight as a draw- check it out for yourself. Hagler KO'ed Thomas Hearns in the 3rd round; but Hearns broke his hand in the 1st round. Gee, wonder if that affected the outcome. Then, as we all know, Leonard beat Hagler in 1987.
Hagler refused rematches with both Duran and Hearns. He hung up his gloves after the loss to Leonard.
So we agree that Robinson is pound-for-pound the best ever; we disagree that Hagler is overrated. I never said he was overrated simply because he would lose to Robinson. He was selective in agreeing to bouts, refused rematches, and only fought about six or seven times in his last five years in the ring.
I say again- no contest here.

A fight between these two would be very competitive for about 6 rounds but I believe that ultimately Robinson would win this one. I don't know if Robinson would knock Hagler out but he certainly has the style and skill level to beat Hagler. This is not a knock on Hagler, one of my favorite all time fighters. Not winning against Robinson shouldn't be equated with being overrated. Robinson is considered the greatest pound for pound fighter that ever lived. If not beating Robinson means a fighter is overrated than Hagler would have lot of company, including Sugar Ray Leonard.

Also, I'm assuming you're referring to Robinson that fought as a middleweight. Robinson was unbeatable as a welterweight, not so unbeatable when he moved up to middleweight, though he was still heads and shoulders above the rest. As a middleweight, Robinson was beaten by Ralph Tiger Jones, Gene Fullmer, Carmen Basilio, Randy Turpin and Paul Pender, and a few others losses later in his career. Though still great he was not unbeatable. I think Hagler was every bit as good as Basilio or Fullmer, maybe better, so we have to give him, at the very least, a fighting chance. Still, over the long haul I think Robinson wins a very tough fight.

Marvelous Marvin Hagler had the ring persona of a caged and food-deprived animal. Along with his workman-like ethic and unparalleled conditioning combined with his ring generalship, Hagler's opponents were said to be never the same after the Brockton, Massachusetts native was done giving them a head-to-toe pounding. Given that, the greatest pound-for-pound fighter of all time, Sugar Ray Robinson, would have had to be in his best shape and right frame of mind when fighting the Marvelous one. I see it as a tactical fight between the ever-flowing and constantly moving Robinson- similar to a matador- to the bull-like, forward-moving Hagler in a fight which would have its share of great moments for both boxers. In the end, I see Robinson winning, but it is conceivable to think it might be too close to call.

Great.
Great.
I mean. . .'Great' verus listing. . .kudos to the bright bulb who suggested this.

There are smarter boxing fans than me. . .and I am willing to change my opinion on the strength of their arguments of persuasion. . .

Hagler was tough as nails. . .but I can't let my g-g-g-generation take away from the skill and career wins of Sugar Ray Robinson- obviously one of the greatest fighters ever.

My money's on Robinson. . .but putting money against Hagler sure scares me.

Boxing fans- please explain your choices. . .I'd love to hear the why's. . .