The Turpin of the first Robinson fight defeats the LaMotta of the sixth Robinson fight. The best Turpin might have been able to defeat the best LaMotta, but Turpin's "window of greatness" was shorter than LaMotta's and his decline more precipitous. LaMotta was at his best from 1942 to 1950, Turpin from '48 to '51.
I’m a big fan of both. Everything you need to know about Turpin can be found in books and documentaries. The deciding factor for me was Randy comes across as a bit slow as a person. Massive talent. But in a sport where tiny margins make all the difference I favour Jake. A more ruthless character with the right temperament. I would probably enjoy a drink with Randy more than Jake though.
Both Great fighters - But I have Lamotta as just a little better in his prime, so he gets a decision.