HOW?????

I think you'll find that this is a better link.
http://igpmanager.com/play/?url=race-result/501991#managers

The answer to your question:

Although you won, there were only 4 drivers. You're clearly more experienced than the other manager, and you're expected to compete in higher populated leagues. Since the other one is new, which was most likely his first or 2nd race, he was not expected to do well, and even though it was only out of 4 and he got 3rd and 4th, it's still considered good.

Daniel R:

you need to comprehend how the game works. :)

Nico explains well the mean.

you have your race points: 25+18   = 43 team points
and the other guy got::  15+12        =  27 team points

http://igpmanager.com/play/?url=race-result/501991#race

That will be added to the season standings for promotions or championship fight
http://igpmanager.com/play/?url=league-standings/4342/3

The managers page:
http://igpmanager.com/play/?url=race-result/501991#managers

Is used for your repiutation points (Nico explains that).
You could watch your world ranking.:

http://igpmanager.com/play/?url=igp-halloffame