<P> The following year on March 27, 1983, the first ever heavyweight title fight scheduled for 12 rounds under that rule was held by the WBC between Larry Holmes and Lucien Rodriguez . The World Boxing Association, from which the World Boxing Organization had not yet separated, later followed suit by voting to reduce their championship distances to 12 rounds on October 19, 1987 . While the International Boxing Federation, which had recently broken away from the WBA, continued to hold onto the position there was no documented medical evidence to show a 15 - round fight is more dangerous than a 12 - round fight, they eventually voted to shorten their championship distance to 12 rounds as well on June 3, 1988 . </P> <P> The last heavyweight 15 - rounder title fight was on October 16, 1987 between Mike Tyson and Tyrell Biggs . The last middleweight 15 - rounder title fight was a World Boxing Board title match on June 7, 1997 in which Jose Alfredo Flores won a split decision over Eric Holland in Ruidoso, New Mexico . </P> <P> In recent years, there have been calls to return the championship distance to 15 rounds . For example, the debate following the Bernard Hopkins - Jermain Taylor fight on July 16, 2005 questioned whether Taylor, who was "losing steam" in the later rounds, would have won the title match were it a 15 - round bout . </P> <P> The shift from a 15 - round to a 12 - round distance for title fights has been controversial . There have been studies which show that the brain becomes more susceptible to damage after the 12th round . Moreover, it has been argued that the 15 - round distance greatly increased the risk of dehydration and exhaustion . </P>

How many minutes are in a boxing round