Each league has it's own pool of drivers.
16 teams 3 tiers that's a pool of 96 drivers to choose from.
If test drivers are added makes it up to a pool of 144 driver to negotiate with.
At the end of the season the teams in the league release their drivers into the pool.
Teams have to try and out bid each other to try and land the drivers services.
Maybe that would allow for offering other teams drivers contracts throughout the season & trying hire them in advance.
Teams can offer a driver contracts between 1-3 seasons there is no renewing the contract once it's completed the driver re-joins the pool, you can not offer them a contract again until a full season has past.
Once a driver retires a new younger driver steps in to their place, all be it he will have zero experience and people will likely not want him but if the drivers experience was changed, it will soon get the driver trained up.
1% gain every time a driver joins a new team at end of their first season.
1% gain for completing 2 seasons with the same team.
2% gain completing 3 seasons with the same team.
Examples of drivers based on this experience points system.
Jenson Button aged 35
his career 1998-persent
8 different teams
8 points for completing 3seasons with teams
1 point for completing 2seasons with a team
17 Total experience
Fernando Alonso aged 33
his career 1999-persent
7teams
4 points completing 3seasons with teams
4 points completing 2 seasons with teams
15 Total experience
Do you still think Alonso is better than Button?
Just because he has been driving in better teams doesn't mean he is a better driver :P