Prime Michael Nunn, who's the highest rated middle he beats? Nunn from the Tate fight or Kalambay ko is a great example of how good he could be.
Could or Would? Coz he could beat any of them. I'd make him a favourite against Ketchel, Tiger and Bob Fitzsimmons (who I rank 6,7 and 5, respectively).
I Iove LaMotta, but Nunn could give him trouble. Southpaw Bert Lytell (awesome fighter) gave him hell.
At his best, verse the top guns best. There's not many I see him losing to, only Hagler, Robinson and Monzon you have to make favorites imo. There are others such as lamotta, Hopkins, McCallum to be considered, there always dangerous but Nunn in prime is hard to beat.