I think Floyd has the best defense according to punch stats (i.e. lowest opponent connect percentage, gap between Floyd’s punch percentage and the opponent’s, etc.). That excludes a lot of the older fighters though.
With the top guys like Whitaker and Benitez, I would say Floyd was the best at ending a defensive sequence with a counter.
I'm pretty sure that Rigondeaux overtook him with that. Also, I think Wladimir Klitschko drew ahead of him right before the Joshua fight. He was using the same kind of jab and grab tactics as Floyd and almost never got hit. Remember that sequence in the De La Hoya fight where Pernell dodged or blocked about twenty punches in a row? I never saw Floyd do anything that impressive. Or when Locche stood right in front of Fuji and dared him to hit him, then dodged punches like he was in the matrix. Floyd never did anything that marvelous.
Wiki says Floyd holds the record at a 16 percent opponent connect percentage on the entry for compubox.
I checked compubox two or three years ago. Rigo was lower than Floyd. The 16 percent was published about him in like 2012 but then he got hit more in the Canelo, Maidana, Pacquiao, and Macgregor fights, so it's probably not 16 percent at the moment. Probably more like 20 or higher. *Okay, I found a more recent compubox total from March 29th 2016. Rigo is at 16.8 and Floyd is at 18.9 for opponent connect percentages with Terence Crawford coming in #3 at 19.3 and Lara #4 at 19.4. **As of Dec 9 2017 Rigondeaux's career opponent connect percentage was 17.1, placing him second in active fighters to Lomachenko at 17 and Mayweather was not listed on the compubox categorical leader ranks. It's also worth noting that compubox didn't even start until midway through Whitaker's career.
So standing one's ground and avoiding incoming punches with minimal movement is more "cowardly" than running around the ring, ducking beneath your opponents' waists, etc.?
When histories great defensive fighters are spoken about Floyd should definitely be in the conversation. Certainly not the greatest tho imo.
Even if Rigo is edging him on that, there are other metrics like opponent's average connect percentage minus connect percentage when fighting Floyd/Rigo or Floyd/Rigo's connect percentage minus their opponent's.
Floyd found his niche in walking the thin line between being an intelligent fighter and being non active. It takes a brilliant mind to fight Floyds style. You can't do it passively. You can't just give it your all, and hope you score a knockout along the way, or get the decision. You have to know where you are in the fight at all times. You need to kind of keep score during rounds. You need to measure stamina across all rounds, as well as your opponents. You can leave no stone unturned when it comes to being aware of everything happening in the fight. And within those parameters you have to deal with the physicality and momentum of the fights. Floyd had a very keen vision of what a successful fighter should do. His theory worked for him brilliantly. I would consider him the most evasive fighter in history. Rigondeaux might have better stats, but he scored those numbers against lesser opposition, over a far shorter career. So you can't draw definite conclusions based on that. In fact it would make no sense.
Interesting stats. & as you stated punchstats isn't that old. What I find astonishing is that for however accurate punchstats/compu box is...Floyd's numbers are based over 20 year period I Just boxrec'd him using your 18.9 ..here is how I see it: Floyd has 18.9% over a 20 year period with 50 fights, totaling 393 rounds. That's unprecedented. Rigondeaux is 9 years 18 fights? That IMO should negate him from the discussion. I'd say Floyd was the most evasive (over the longest period of any fighter) Roy Jones had a smaller timespan where he dominated, but I do recall his fight with Paz was supposed to have been the first time punchstats tracked a fight where a fighter went a whole round without landing. I think RJJ was more evasive based on talent. His reflexes were ridiculously freakish. But without skill to replace what he lost when youth expired...