Mayweather. Personally, I think Floyd is the defensive goat both in and out. That forearm thing, though...
Toney had a ton of off nights. Toney spent plenty of nights in the pocket and eating some nasty shots. But thats Toney for you. He loved that ****. So it's hard to gauge just how good he was.
Locche, Whittaker, FMJ, and Toney are all good shouts. All time though, thats something you should really have to sit down and think about, though the ones people list out off the top of their heads, there is a reason why you dont have to put a lot of thought into them because they were that good.
In a true phone booth, I would argue Roberto Duran was the best defensively, but he did get hit a little when he was at middle to long range. Toney is right there with Duran defensively on the inside. At middle range, many fighters can be argued as the best defensively at this range. James Toney, Wilfredo Benitez, Pernell Whitaker, Bernard Hopkins and Andre Ward along with a few others. I know this is not part of the question but I will inject that some of the best defenders from long range include Floyd Mayweather (although he can defend well anywhere in the ring) and Julio Cesar Chavez (he did get hit some in the pocket and at close range).
Great post and analysis. As an add on -- think Lomachenko has proven that he is one of the most brilliant defensive fighters currently fighting, and he's proven that adeptness at long, mid, and close range, though I think he's clearly most comfortable and at his best at range, both long and mid. Ive never quite seen anything like him before. And you have to see it to believe it, a come-forward type pressure fighter who is at his best coming forward and an offensive-minded fighter and at the same time unbelievably defensively responsible, aware, and brilliant.
James Toney. Floyd is very good in the pocket but not 12 rounds good. James Toney at his best can stay in the pocket a full fight, I've never seen Floyd do it for 12 rounds.
Toney and mayweather will be the first to come to most fans minds i reckon Edit : shout out sweet pea