Conn simply had too much class and experience at his best for Leon to compete with. What was actually Leon's best career performance? I favor his ninth round TKO of the big and deadly punching Bernardo Mercado (right at the Colombian's own career peak), to earn his second shot at the HW Title. (Leon was also on fire and really had his head on for the Easton Assassin, but that was at a moment in time when Larry was, in my regard, one of the three greatest HWs ever. Still, Leon actually stole round two from Holmes when Larry was losing very few rounds.) Because of what Leon did to Mercado, I consider him to have been a bona fide HW, and there's no way any version of Ken Norton (even the peak Jerry Quarry edition) somehow survives the early rounds against Bernardo, raising serious questions about who actually the world's best HW was between Leon-Ali I and Holmes-Shavers I. Of course Leon was rarely on fire, but when he was for Mercado he was very, VERY good. However, the Pittsburgh Kid was in an entirely different league than Leon, and late in life, in a televised interview, Joe Louis said, "Billy Conn had it all!" The guy was 59-9-1 for Louis I, and left a barrel of Champions, legendary ATGs and other notables in his wake for a ridiculous measure of experience. After Mercado, Leon was still only 10-2-2. At full strength and peak conditioning like he was for Bernardo, there's simply no way Conn stops him, and I don't see Billy attempting to. He was able to stun Louis because the Bomber was underweight and weakened (much like Leon himself was at CW for Qawi). Leon simply had too much heart and drive for Conn to hurt him. Leon was at 205 for Mercado, while Conn entered 1941 with only nine career stoppages. Conn via lopsided and unveventful UD over Leon.