Here are your options as I see them:
1. Step back, let the rookies drive, and possibly suffer performance loss due to lack of experience.
2. Drive, and let the rookies have their turn next year, When option 1. will take over, because you can't drive anymore.
The way I see it in my situation is... I have spent 3 years cultivating my driving skills, why step out when I am at my "prime". This is as well prepared as I will ever be to drive a FIRST robot in competition, and I think it would be a shame not to use me. Next year, a rookie who has a large hand in building the robot will take my place, and the cycle will start all over.
I can train the drivers during build season...without them driving in a competition.
This next part isn't really on topic, but If any of the seniors in the driveteam ever asked to drive the robot, I would not hesitate to let them. They already know the pressures of being in the box, and anyone can figure out how to steer a robot.
Besides, training new drive-teams is what off-seasons are for.
