Glossary of Motorsports Analytics Terminology

Age Curve – a depiction of an average NASCAR Cup Series driver’s career, based on PEER, that displays prime and decline. The Age Curve prior to 2017 is as follows:


APE or Adjusted Pass Efficiency – the percentage of pass encounters resulting in a driver’s favor; in essence, the measure of passes versus times passed. Omitted are track position changes away from the racing surface (i.e. green-flag pit cycle position shifts) and passes on restrictor plate tracks, road courses and dirt tracks, where pass encounters are more volatile and less reliable.

Average Green-Flag Speed Ranking – the season-long ranking of a team’s per-race average green-flag speed ranking.

BRP or Base Retention Percentage – the percentage in which a driver and team retain their RZS in the final 10 percent of a race.

CRASH or Crash Frequency – the number of crashes per race for a single driver. In all instances, a crash is defined as a wreck or spin that causes the driver to lose track position.

DEV or Finish Deviation – a measure of the consistency of a team’s average finish; the closer the deviation is to zero, the more reliable the average finish mark becomes.

Jumping — the act of gaining positions during green-flag pit cycles either through short-pitting, long-pitting or sheer speed of the pit stop.

PASS EFF or Pass Efficiency – the percentage of pass encounters resulting in a driver’s favor; in essence, the measure of passes versus times passed. Without omissions.

PEER or Production in Equal Equipment Rating – a proprietary measurement that handicaps team and equipment strength in an effort to isolate driver production.

PRD or Position Retention Difference – the percentage difference in running position in the final 10 percent of a race.

PROA or Production Rating Over Average – the difference in a driver’s PEER and the average PEER for a driver of the same age.

Red Zone — a term coined by NASCAR crew chief Greg Erwin that refers to the final 10 percent of each race.

  • RZS – indicates a driver’s average red zone starting position
  • RZF – indicates a driver’s average red zone finishing position

RELEV or Relevance Percentage – the percentage in which a driver or team finish inside the top half of fields. Start-and-park drivers are omitted from field count for all short track division statistics.

RET % or Restart Retention Percentage – the percentage in which a driver successfully defends his or her position in the two laps following a start or restart. In all instances, only restarts inside the first seven rows are measured.

SPV or Surplus Passing Value – the difference in a driver’s single-race adjusted pass efficiency and the expected APE of a driver with the same average running position in the given event.

TCF or Terminal Crash Frequency – the number of crashes per race for a single driver that result in too much damage to continue competing.

T15E or Top 15 Efficiency – the difference between the percentage of races finished inside the top 15 and the percentage of laps completed while inside the top 15.

4QSR or Fourth Quarter Speed Ranking – the average of the per-race average green-flag speed ranking, specifically in the final 25 percent of the race.

 

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