upon any suspension adjustments performed and the quality of the crew. NASCAR Cup Series team pit strategies vary widely, depending on the track. Fuel is generally a more limiting factor than tire wear, and the phrase "fuel window" or "pit window" is used to indicate the maximum number of laps possible with a full load of fuel, assuming continuous green flag conditions and a small reserve. The window is used to calculate (or recalculate after a stop) the minimum number of pit stops required to complete the race. The road courses on the schedule may see as few as two scheduled stops; oval race tracks generally see between four and six scheduled stops. Races at short tracks such as Bristol Motor Speedway and Martinsville Speedway are short enough to be completed with only two scheduled stops for fuel, but teams plan on more stops due to rapid tire wear and significant loss of cornering speed on worn tires. If one team pits for tires and is considerably faster (between 1 and 3 seconds per lap), then teams will usually follow quickly to avoid losing time. Pit strategy can play a significant role in the outcome of a NASCAR race, perhaps more so than other racing series. Under caution, most teams use similar strategies to avoid being caught alone, typically following the leader's decision to stay out or pit, but sometimes teams will deliberately pit "off-sequence" if they feel they can gain an advantage later. Race tactics can affect strategy as well. Late in a race, drivers can reduce throttle input to save fuel at the cost of slower lap times, but by doing so they can stretch their pit window to the end of the race and skip the final pit stop. A late caution can force teams to make a tough call: Stay out on worn tires, or pit and give up track position. The green-white-checker rule can cause headaches, as it can potentially extend the race an unknown number of both green-flag and yellow-flag laps. Furthermore, strategy can be determined by qualifying position. A team that qualifies in the top six positions will have the best choice of pit stalls, most often choosing the first, last, or a stall with an opening either in front of or behind that one. A team that qualifies deeper in the field will have a greater opportunity to be stacked behind cars