I'm 5' 8-1/2" tall. The abdomen measurement is tough for a couple of reasons; I will say that if I lay flat on my back on a hard surface (floor), I can easily sink my gut down to a level at least a probably three inches below my rib cage. I am 65 years old, so some of that may just be that my abdominal muscles are simply not as tight as I would like them to be, no matter how much I try to work them.
FWIW, my weight of 165 lbs is dead on accurate as my home digital scale agrees exactly with the scales at the offices of both my regular doctor and my cardiologist. Maybe I am just measuring my abdomen incorrectly or inaccurately. As I said, I wear 33" Levi's 505's and they are actually a bit loose in the waist; I also own a few pairs of 32" waist 501's and look pretty good in them, although they are a bit edgy on the waist size.
I am at the gym five mornings a week and do a lot of cardio to help keep my weight down. I'm considering hooking up with a trainer for a few sessions for some guidance on other stuff; I've only been hitting the gym for about 18 months - the last time prior to that was in high school. I dropped 30+ pounds in the first four months and have kept it off, +/- 1 or 2 lbs, for the last 14 months. I'm determined to continue at no higher than my current weight (preferably maybe 5 lbs lower) for the rest of my life.
BTW, you mentioned earlier "your sport" - what sport would that be?