Introducing gRating: iRacing’s iRating for NASCAR

Median gRating Shifts over Time

The median gRating has drifted significantly over time. In the early years of the modern era, ratings slowly climb to a median near 1,500, then explode in the late 2000s until finally settling down in the NextGen era. To effectively compare gRatings across eras, we use an adjusted gRating that measures a driver’s performance relative to the rest of the field at that moment rather than against a fixed historical scale. Each race’s gRating is centered on the rolling field median and scaled by the field’s typical spread, with additional adjustments to prevent early seasons and short careers from producing exaggerated results. This allows the adjusted gRating to reflect how strong a performance in context, independent of era. Because of these adjustments, adjusted gRating does not directly map to the probability of scoring more points.

Even with this adjustment, comparing across eras directly remains difficult. The performance of some drivers gradually declines late in their careers, while others leave the sport while still near their peak. To account for these differences, I’ve augmented gRating with gPace (gRating Performance Across Career & Era). gPace considers multiple aspects of a driver’s career gRating, including their median performance level, the rate at which they exceeded the field per race, their career trajectory, their total accumulated excess gRating, and their consistency. These components are then normalized per-race and mapped to a 0-100 scale.

Interpreting gRatings

Drivers start out with a gRating of 1,350. The best up-and-comers typically quickly grow to the 1,500 range. Drivers in top-tier equipment generally sit around the 1,650 range. Drivers commonly experience their peak gRatings in the first few races of a season after a championship run. Drivers who move from mid-tier to top-tier equipment generally see their gRatings rise by about 150 points, which typically takes 1/2 to 2/3 of a season. They usually hover around their current gRating as they settle into the equipment and team, before their gRating quickly grows. From 1972 to 2002, and since 2022, drivers have rarely fallen below 1,200 gRating, as drivers would promptly be replaced if their performance was that inadequate. The exception from 2002 to 2021 aligns well with the start-and-park era; it isn’t necessarily that those drivers were so uncompetitive, just that they finished at the back of the field in nearly every race because they completed only the bare minimum laps.

Interpreting gPace

The Top 15 Drivers by gPace

Jeff Gordon just pips Dale Earnhardt for first in the top drivers ranking, driven by much higher career consistency and a stronger excess gRating across nearly 25 seasons. Jimmie Johnson sits lower than expected in 7th, likely influenced by both his and career crew chief Chad Knaus’s emphasis on optimizing for the Chase format and by the long post-peak tail of his career. Tony Stewart and Kevin Harvick also fall just below the top tier, reflecting careers defined by adaptability and reinvention across eras, not by uninterrupted, race-to-race dominance at the very top of the field.

Six of the drivers are active, with all but Kyle Busch still in peak form. Denny Hamlin and William Byron are the only active drivers who have yet to win a championship. While Denny ranks 5th overall and best among active drivers, he has not yet eclipsed Mark Martin as the best driver never to win a championship. Jeff Burton is the last driver on the list to have never won a championship. Denny, Mark, and Jeff’s inclusion on the list underscored that sustained week-to-week strength is more critical to gPace than championship wins. Methodologically, gPace and the adjusted gRating favor drivers who combined high peaks with long-term consistency, elevating careers like Gordon and Martin while tempering drivers whose resumes were shaped more by short peak windows, format optimization, or pronounced late-career decline.

Current Drivers gRating

gRatings are a great tool for Let’s dive into the 2025 season. And the top 10 current Cup Series drivers by adjusted gRating see how their careers evolved.