Forza Motorsport - Skill Rating

This is a graph of my Skill, Safety and XP ratings over time.

The chart shows changes to each of the following scores over time.

• Skill
  I'm pretty sure this is built around the Segment Score concept which is shown in game at the top right of the HUD. It describes the players ability to follow the racing line without going off track or hitting other cars. There is also an element of speed through the segment. Finally, and arguably the biggest differentiator of skill is success/failure against other players with your score adjusted based on their individual skill levels.
• XP
  Basic experience of the game. More races = more experience.
• Safety
  Safety rating. S (Good) A, B, C, D, E (Horizon Superstar). This is basically a measure of how much trouble you find yourself in. There is no built up good will with the safety rating. Any 2 or 3 consecutive incidents can be enough to drop you a level while it takes about 2 - 10 clean races, depending on the severity of the initial incident, to get back again.