Complex sentence: He was the Fleet boxing champion for four years: 37 KOs and only retired from the said position because he couldn't find someone brave enough to challenge him, he also has his own gang of men following him around.
Split into simpler sentences: He was the Fleet boxing champion for four years: 37 KOs and only retired from the said position because he couldn't find someone brave enough to challenge him. Simpson also has his own gang of men following him around.