wraptureSorry didn't see it.
At a certain level - usually when he's over 75% full on his "Experience" meter - a driver's skills seem to start falling off, sometimes drastically, and he'll start making Zero-Bob mistakes and costing you races. At that point, it's time to retire him and start training a new Bob. I've retired several - some because they were past their prime, some because they just pissed me off at the wrong time by not listening. I'm a harsh taskmaster at times, it seems.
Is it actually 75%? I've read on here from some posters this happens after the bar is completely full.
Driver Skills start dropping at about 75% of the race life.
you only need to keep a driver beyond that if you care about boring trophies. Any more races after this point ofline and Drivers continue to lose skills.
Time for them to buy a golf course and get a job on Fox Sports instead.