[Ilmari Ylitalo]

It's the last statistic determining your championship position is all other stats are equal. Meaning same total points, same amount of wins, position 2s, 3rd, etc. So, if you've gotten smaller number that your rival, you've either raced better on average, or gotten your merits by doing less races overall. I doubt it has ever gotten to the situation that SP would have ruled the champion, but in theory it's possible.