The change prompted a call for competitors in the Mustang Madness class to select a fixed index (a non-changeable e.t.) based on eighth-mile data that was gathered during time trials and qualifying sessions. Unlike the class’ usual race procedure, the 0.1 breakout allowance was not used with the fixed-index format. A review of those timeslips showed us that ’Sleeper covered the eighth consistently at 10.364 and 10.372, so the quicker e.t. was selected as our permanent index for the event. Like bracket racing, index-style racing requires drivers to run at or as close to their index number as possible without going quicker than that number (breaking out), while still reaching the finish line first. The difference between the two is that a dial-in number in a bracket race can be changed.