The WBC has a unique rule for bouts that were subject to purse bids. Under that rule, 10% of the bid is paid to the winner of the fight. When a WBC mandatory title defense goes to purse bid, the auctioned amount is divided 90% for both boxers according to the corresponding purse split of such fight but 10% is left to be a bonus for the winner of the fight. That is, the winner, in addition to being recognized as WBC champion and earning the corresponding percentage of the bid, takes 10% of the total purse, thus giving great additional incentive. Last weekend at the Center Videotron in Quebec, this rule came into play when WBC / WBO / IBF light Heavyweight Champion Artur Beterbiev retained his titles by knocking out former former super middleweight champion Callum Smith in the seventh round, earning the 10% bonus in addition to his salary for the fight, meaning he earned an additional $211,500.