Extremely ... he had a killer jab, in his prime very good speed and a variety of well schooled punches thrown in combinations ... he could also box lefty or righty ....
I've always felt that being able to switch from orthodox to southpaw at well, and do both well is worth serious credit by itself.
Hagler was seriously good he had a great variety of shots, very good positional sense ,excellent foot work and balance.Marvin was allways in position to throw another punch if the first one missed,he understood pace and how to judge it,he was a ring mechanic of the first order,a fighter who honoured his calling.
Same kind of fighter as Carlos Ortiz. Like McVey said, a mechanic - about as good as any fighter can get. The only ones slightly better are those once-in-a-blue-moon specials like Roberto Duran, Willie Pep or Ray Robinson.
Marvin's exhibition against the Big Punching Tony Sibson is a perfect example of Marvins versatility, in choosing to initially Box a potentially very dangerous opponent. excellant skill and mobility
Funnily enough, I rarely see mention of how good Marv's defence could be in his prime. Many times that it looks like he's been hit, on slow motion, he's JUST slipped the punch and is now in position to counter. His jab was an ATG one in my book. He busted up fighters badly with it ... like a MW equivalent of the heavy Liston or Foreman jabs, but much more fluent.
Put his punches together very well, was adept at slipping, parrying and blocking shots, and had a knack for creating optimum angles for his shots. Plus his punching technique was superb from either stance.
Hagler's boxing skills are somewhat underrated IMO. At his best he was one of the most highly skilled MW's there was. Excellent footwork, in an economical not flashy way. Good head movement. Good feints. Threw hard, fast intelligently placed combinations and was adept at slipping and countering. Oh yeah, can't forget his concrete chin. If I sound a little biased then I'm guilty as charged but I've always felt that overall he's the best MW champ of all time. Not by a wide margin mind you but still the best.