Complex sentence: Jonathan Kimball Keyworth (born December 15,1950 in San Diego, California) is a former American football running back in the National Football League for the Denver Broncos for his entire career from 1974-1980.
Split into simpler sentences: Jonathan Kimball Keyworth (born December 15,1950 in San Diego, California) was a running back in the NFL. He played for the Denver Broncos for his entire career from 1974-1980.