The beauty of pro boxing aside from the art and style itself, is the process of how the sport is made for those with weak chins to get weeded out as they fight others to climb up the ladder. The ones with weak chins gets KOed and usually they either readjust themselves and become great like Manny Pacqiuao, or they retire or they go on to fight in other combat sports (Anderson Silva got TKOed in his first pro boxing match. Rey Sefo got KOed in a boxing match and ended up leaving the sport to do K-1 full time, yet he was known for having a granite chin in K-1). The exception to the rule is if a boxer has really incredible reflexes with great defense which makes it hard to hit him until his chin finally gets exposed later on in his career (Roy Jones Jr). Last year in 2015, Mike Perry got KOed in a pro boxing match. The dude he fought was throwing feint jabs to his body and quickly followed with a overhand that dropped Perry. In MMA you have fighters whose primary style is not boxing so they go on to learn the basics of the sweet science but do not advance as much as other may. Perry has so far fought these type of fighters and has looked as if he is a Golden Glove Prodigy....When in reality he is a fighter with good basic boxing which is complimented by his power. BUT his chin has been checked and exposed. Any fighter with good enough boxing skills that watches his pro boxing fight will know this and feel confident that they can take him out.