Fox you have to pick team every week
Nascar you can keep your team for the year just make sure
you pick bonus points (winning driver & MFG.) every week
YAHOO LEAGUE you can only use a driver 9 times throughout the year (read rules real close)
Maximum Start Details
Each driver in Yahoo Sports Fantasy Auto Racing can be an active member of your team in no more than nine races.
For the purposes of this game, a driver must be active for a race (not during qualifying) in order to receive credit for a race started. Likewise, a driver who is on your team but stays in a reserve position during the race does not get credit for a race started.
Once a driver has reached the nine-race limit, he will no longer accumulate any fantasy points for your team even if he occupies an active roster spot. This limit does not change no matter when you join the game.
Your driver's start totals will not reset at that half-way point of the season. If you start your driver nine times during the first half of the season, he will not be eligible to earn ANY fantasy points (neither qualifying nor start points) for the remainder of the season.
If you reach the nine-race limit for a driver on your current roster, you will not be able to release him and subsequently reacquire him. You may keep the driver on your roster, but he will no longer accumulate any points.
If a driver is on your active roster for a given race but does not drive in that real-life event, he will not be credited with a race started.
The number of races each player has remaining for you will be listed along with all of his other stats.