Nah, he's pretty clear. He says he's a 6 and Yusuke is a 10, but he has the advantage because he's been fighting longer and has better technique and stuff...at least in the dub.
How far into the fight are you? Knowing Sensui He honestly might have been BSing.
--- "She was like, 'Oh, did you see that firefighter? Hes so cute.' And I was like, Mom, I just got blown up."