Floyd Mayweather -- Ray Rice Isn't the Worst Wife Beater ... He Just Got Caught

Floyd Mayweather says Ray Rice is far from the WORST of the domestic abusers in America -- only problem is that Ray got caught on video.

Mayweather -- who spent time in jail for beating up his baby mama a few years ago -- spoke to Fight Hub TV and said he's pulling for Rice ... "I wish something positive out of the situation."

And that's when Floyd tried to explain why Ray's attack wasn't that bad compared to other wife-beaters -- "[There are] a lot worse things that go on in other people's households also ... it's just not caught on video."

There's more ... when asked about his own domestic abuse case -- Mayweather used the O.J. Simpson defense to try to explain why he was wrongly convicted a few years ago.

"I'm pretty sure that with my situation, no bumps, no bruises, no nothing ... with OJ and Nicole, you seen pictures. With Chris Brown and Rihanna, you seen pictures. With Ochocinco and Evelyn, you seen pictures."