re: What is your estimated total wins/losses from sports betting?

I've only been gambling for 5 years now (only 23) with the spare money I kept from my paychecks (Barracks life has its benefits)...

I know for the first 3 years I was down right around $4000.
Last year (I mark my new year every end of the football season) I went on a tear. I made just shy of that $4000 back.
This year, I'm back up a lot, up nearly 190 units.

As dgtiger said, it's all about money management. My biggest issue at first was chasing losses or increasing unit size when I was on fire. I've figured out that by betting the same amount each game (I now have maybe 5 2 unit+ plays a year), it's a lot easier to come away profitable.