With there being twelve racers, the win-loss record means something different than simply 1st = win and last = loss. For every racer that you place ahead of, you get one win, and for every racer who places ahead of you, you get one loss. I like this system, because it doesn't put so much emphasis on placing in 1st. In a twelve player race - especially a Mario Kart race - even coming in 5th can still be an accomplishment.
If you place first in a twelve-player race you'll get 11 wins, so you could reach 250 wins in as little as 23 races. There's that number again...