It used to be a tradition in a lot of the big fights that a chief sparring partner from one main event camp would be matched against the chief spar mate from the other camp. I believe this was something Ali did a lot, and others around that time (and perhaps going back far before). Can anyone name any of these matches? And when did this stop being standard practice? I know the sparring partners loved it because they not only got paid to spar, they also got a fight and an extra payday. And promoters had to like it because it was cheaper than putting another title fight or match between contenders on the undercard.
It goes back before this but Jimmy Delaney (sparring partner for Tunney) fought Tommy Loughran (sparring partner for Dempsey) on the undercard of Dempsey-Tunney 1.
