I believe that the score you get for each win and each loss is so that everytime someone submits a new deck, it starts around position 250 with 0 score. So, if people around position 250 have a higher score than 0, the losses will start taking more points, and if people around 250 have lower score, it will start giving higher score.
Zanz made this so you can't get autokicked of arena when you submit.
Correct me if im wrong, but i think Jappert got his wins with a more favourable ratings.
EDIT: I see you say you're 8 and Jappert is 9, why wouldn't it make sense you had more wins and less losses?