Complex sentence: Keith Tapia (b. September, 1990) is a Puerto Rican amateur boxer fighting out of the Bronx, N.Y. who has won several youth tourneys for the US and Puerto Rico.
Split into simpler sentences: Keith Tapia (b. September, 1990) is a Puerto Rican amateur boxer. Fighting out of the Bronx, N.Y., he has won several youth tourneys for the US and Puerto Rico.