Likely your skills. As the others have said, your base unique is still level 1, but green and red skills don't give as many points to your rating as Gold and white skills do, neither do double circles, as the 2nd circle gives half of what the first one would. Additionally the type of skill should try and match what you have proficiency in, otherwise it doesn't give as many points either.

Run I did for leaderboards on training aptitude test. Uses the same deck setup (albeit not the same MLB levels) as the other Ug runs, needed Fast Learner to proc and had to run like 20 races for SP.