Complex sentence: He was the British Judo Association National Coach for Over 15 years, coached at 4 Olympic Games, and his players have won 6 Olympic Medals and 14 World Championships.
Split into simpler sentences: He was the British Judo Association National Coach for over 15 years and coached at 4 Olympic Games. Competitors that he coached in that time won 6 Olympic Medals and 14 World Championships.