Analyzing the Live Timing - ChampCar Road Atlanta Edition

It is difficult not to be impressed by the live coverage put out by the ChampCar team considering it is an amateur racing series. So when I tuned in to this year’s race at Road Atlanta, I was pleasantly surprised to find live timing, a live stream, on-board footage, and even pit lane commentary!

Of particularly interest was the live timing which pulled the most up-to-date race data as a JSON file. By extracting the underlying data and running it through custom plotting routines, it becomes possible to perform advanced lap time analysis more commonly seen in higher levels of motorsport.

Lets see what we can learn from the lap time data of ChampCar’s 2018 14-Hours of Road Atlanta.

Overall

First, we explore the race as a whole to see the overall level of performance between the teams. This lets us get a feel of how competitive the race is.

Best and Average Lap Times

Each team’s best and average lap times are plotted in a bar chart in order of place finishing. In this plot, ‘average’ refers to the overall average of the event. In other words, the average is the total runtime of the event divided by the number of laps.

Best lap time does not appear to be an indicator of placing or average lap time. It is a reminder of how important consistency, not raw performance, can be in endurance racing.

Box Plot

The box plot is another way of understanding how each team performed relative to each other, this time emphasizing the distribution of lap times rather than the best and average times.

The top third of the pack has good overall pace with good median times and tight control of their lap times. Further down the pack we see more variation between the teams. Some teams have good pace but are likely losing time in the pits. Some teams lack the pace and/or the driver who can consistently drive the car to its full potential.

Rising Lap Time

The rising lap time shows each team’s lap times in ascending order. Although we cannot identify specific teams in this particular graph, it is still interesting to see the consequence of each team’s unique situation.

Best lap times are contained within a ~10 second band, showing how close the teams are in terms of raw lap time performance. Larger differences are seen as lap times rise, highlighting when cars begin to break down and enter the pits.

Top Five Teams

We can observe specific differences between teams by focusing our attention to a subset of teams. We will start by following the top five finishers of the race. These teams are:

• Car #146 - Huggins (Pinkies Out)
• Car #213 - 23 Van Winden Racing
• Car #935 - Team Jacky Ickx 935
• Car #187 - Team Punisher
• Car #19 - Team Infinite

Race Position

This plot shows the progression of a team’s race position over time. It shares the story of how the teams got to their finishing position relative to how they started.

It is possible to recover from a poor start and still place within the top five. Team Jacky Ickx 935 made a fine recovery from the back of the grid, ultimately placing third by the checkered flag.

Rising Lap Time

The rising lap time is a way to describe the distribution of lap times over the course of the race. Comparing where the lines intersect relative to one another highlight the relative strengths and weaknesses of each team.

Huggins (Pinkies Out) has the fastest car and outperformed the competition in terms of pit stop time. 23 Van Winden Racing and Team Jacky Ickx 935 have great consistency, but ultimately did not manage their slower laps and pit stops as effectively as Huggins (Pinkies Out).

Box Plot

Like the previous plot, the box plot describes the distribution of lap times but as a more conventional visualization.

The top four teams have similar median lap times, but differ in their distribution. Team Punisher has similar raw lap time performance to race winner Huggins (Pinkies Out), but ultimately lacked the consistency to maintain the pace.

Outing Accumulating Average

The outing accumulating average is the average of all the laps up the current lap. It helps show the outing progression over time without highlighting lap-to-lap variation.

We already discussed the lap time performance of each of these teams, so there is no new information in that regard. Of greater interest is the profile of each curve. We can see different profiles within teams, suggesting a change of driver with a different driving style.

Top Two Teams

We can focus our analysis to the individual team level to gain further insights into their unique performance characteristics. We narrow our scope to the top two race finishers:

• Car #146 - Huggins (Pinkies Out)
• Car #213 - 23 Van Winden Racing

Box Plot

We have used the box plot to visualize the distribution of the lap times, but this time we can observe the distribution for each outing.

The difference in strategy and consistency is clear. 23 Van Winden Racing is more consistent between outings while Huggins (Pinkies Out) strived for raw lap time in some outings. Interestingly, 23 Van Winden Racing has a lower median lap time than Huggins (Pinkies Out). Although 23 Van Winden had the pace to be race winner, the race was ultimately won by managing the slower laps and pit stops.

Pit Times

Pit-in laps are identified based on the minimum pit time requirement. We can compare pit-stop performance by observing the lap times containing a stop.

Huggins (Pinkies Out) has an advantage with one less pit stop than 23 Van Winden Racing. Huggins (Pinkies Out) show excellent consistency between pit stops, exemplifying their reliability and skilled pit crew. That is not to discount 23 Van Winden Racing’s excellent showing at this race, though the extra pit stop and extra time in outing #5 did not help them get closer to winning the event.

Conclusion

Advanced lap time analysis need not be reserved only for highest levels of motorsport. Even at the amateur level, useful insights about the competition can be drawn from the data. Congratulations to Car #146 Huggins (Pinkies Out) for a well deserved race victory!