Leonard was a bit faster, and would probably be a step ahead throughout. Curry was beating McCallum to the punch consistently IIRC, before McCallum was able to one-shot DC...something he wouldn't be able to do to Leonard. SRL probably around 145-140 on the cards.
I think McCallum's pace, fundamentals, body work, and power eventually tire out Leonard, and he gets either a late stoppage or a close but clear decision. Leonard will definitely have success early on with his speed, but I don't think he'd be able to keep McCallum away for long. McCallum was a master of finding those body shots that take a lot out of a fighter, and his power at jr. middleweight was elite. So I think he eventually takes over and wins late.
Both great fighters but Leonard's all wrong for McCallum and the former's speed nullifies the latter's offense much of the time. Leonard by at least nine rounds on all three cards.
Sugar Ray was his best at welterweight. Ayub Kalule dropped him at jr. middleweight. So would McCallum. I'll take McCallum.
SRL all day. An ATG speedster is kryptonite to McCallum. Leonard had the power to keep him honest too, Curry hurt him noticeably twice. There's no chance he stops Leonard who was a long range specialist when people could take him that deep. Duran pounded Leonard's body bigtime in their first bout and Ray still came back to win the last couple of stanzas, so Mike's vaunted body attack won't save the night either. It's be a fun watch with Mike a step behind most of the night.
We can disagree on that one. He fought superbly against a very awkward opponent in Kalule. He's just too fast, too classy and too durable here.
Either Ray stays on his bike all night or McCallum wears him down. With this being suggested as a 15 rounder, I'm taking McCallum to come of late. Speed and working outside was definitely the way too beat McCallum but it's still not easy, especially over 15 rounds at 154.