Watson can't beat Kalambay. He was a gorgeous fighter, one of my very very favourites, but he boxes within certain limitations that cannot be breached. There was something frightening and interesting about him at 168lbs but still.
Watson would do better against Kalambay than he did McCallum, McCallum broke down Watson on the inside with body punches. Kalambay would be boxing on the outside, with Watson as the aggressor. And it would be in my opinion a competitive tactical fight, with Kalambay's extra bit of class being the difference winning a closish decision.
I like Kalambay in a intriguing fight, by decision. This would be one for the fans of middleweight s.