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PHOTO: INDYCAR, JOE SKIBINSKI

Pit strategy’s impact on the IndyCar podium at Long Beach

No one will accuse the IndyCar race at Long Beach of being a thrilling race. It wasn’t all boring though: the pit strategy that was used during the final stops of the day was fascinating. Each of the podium finishers used a different strategy, and those strategies, combined with each driver’s pace and a miscommunication, had a massive impact on the finishing order in the race.

On a road or street course, a car is nearly always faster running alone than in traffic. An effective pit strategy selects a time to stop that maximizes the time a driver spends running alone. Two examples of this happened at Long Beach. First, Scott Dixon was being held up by Helio Castroneves by 1.5 seconds per lap, and both drivers needed to make a pit stop. Dixon pited one lap before Castroneves and had clean track to use for one lap after making his pit stop. The clean track allowed Dixon to complete the lap after his pit stop 1.5 seconds quicker than Castroneves, and Dixon was ahead of Castroneves by the time Castroneves returned to the track after making a stop. A similar pass was performed by Simon Pagenaud, who gained clear track by pitting two laps later than Castroneves.

I analyzed the lap and sector times of the podium finishers, Helio Castroneves, Scott Dixon, and Simon Pagenaud, to see how effective each strategy was at giving a driver clear track to run on. These laps included each driver’s ‘in’ and ‘out’ laps, the laps directly before and after the driver made his pit stop. ‘In’ laps are highlighted in red, while ‘out’ laps are highlighted in green.

Screen Shot 2016-04-24 at 5.01.09 PMBefore analyzing the data, we pause for an explanation of sectors. IndyCar divides each lap into subsegments called sectors. The Long Beach track is composed of nine sectors, named Sector 1 through Sector 9 respectively. After each race, IndyCar publishes each driver’s sector times in a PDF file that is available for download from their website. All data in this article comes from that file.

At Long Beach, pit road runs from the start of Sector 9 to the end of Sector 1. When a driver pits, he must slow to pit road speed before entering the pits at the beginning of Sector 9, meaning he must begin to slow to pit road speed while in Sector 8, increasing his time in that sector on his ‘in’ lap. Similarly, he must maintain pit road speed until exiting the pits at the end of Sector 1, which means that his time in Sector 2 of his ‘out’ lap will be higher than it would be on a normal lap.

Now on to the analysis.

At the start of Lap 51, NBCSN showed that Helio Castroneves led Scott Dixon by roughly one second, and Simon Pagenaud by roughly two seconds. Castroneves caught backmarker Jack Hawksworth as he approached Turn 1 on the start of Lap 51, but was unable to complete the pass. Castroneves would remain behind Hawksworth for the next two laps until both cars pitted at the end of Castroneves’ 52nd lap.

The time Castroneves spent behind Hawksworth at the end of Lap 51 and during all of Lap 52 eliminated any chance Castroneves had at a victory. Scott Dixon pitted at the end of Lap 51, and used the empty track in front of him on Lap 52 to jump ahead of Castroneves. From the beginning of Sector 8 on Lap 51 to the end of Sector 2 on Lap 53, Castroneves was 2 seconds slower than Dixon. About 0.5 seconds of that gap was from time spent slowing to pit road speed, pitting, and returning to race speed. The other 1.5 seconds of that gap was from time on the track at race speed.

Screen Shot 2016-04-24 at 5.13.56 PMThe chart to the left compares sector times of Castroneves and Dixon from Laps 51 to 53. Each sector from each lap is identified by the lap number first, followed by a period (.) and the sector number, so 52.2 represents Sector 2 from Lap 52. Yellow cells indicate that a driver was slowing to or accelerating from pit road speed in that sector. Red cells indicate that a driver was on pit road in that sector.

 

Race winner Simon Pagenaud was the last of the podium finishers to make his final pit stop. He used Lap 51 to ‘move up’ into the space Dixon vacated behind Castroneves. Pagenaud was depending on Castroneves to maintain a decent pace until Castroneves stopped at the end of Lap 52.  Had Pagenaud been held up too much behind Castroneves, it would have allowed Dixon to take the lead when the cycle of pit stops was complete. After Castroneves pitted at the end of Lap 52, Pagenaud made the most of the clear track by laying down a blistering 68.9 second Lap 53, and an impressive 76.7 second ‘in’ lap on Lap 54. Overall, Pagenaud was 1.3 seconds quicker than Dixon from the start of Lap 51 to the end of Sector 2 on Lap 55. Pagenaud’s ‘out’ lap on Lap 55 was slower than Dixon’s, but by that point it was too late for Dixon to respond because Pagenaud had grabbed the lead when he returned to the track after making his pit stop.
Screen Shot 2016-04-24 at 5.25.17 PM

Unfortunately for Dixon, a miscommunication almost certainly cost him the lead on Lap 55. After the race, Dixon stated that he had already started saving fuel on Lap 54, the lap when Pagenaud made his final pit stop, because he didn’t realize the pit stop cycle was still happening.

Dixon’s lap times support this claim. Dixon completed Lap 54 in 69.9 seconds. However, his average lap time for Laps 48, 49, 50, and 53 was 69.6 seconds. (Laps 51 and 52 are excluded because they were his ‘in’ and ‘out’ laps, respectively.) It appears that Dixon gave up three tenths of a second while saving fuel on Lap 54. That time, combined with an extra use of ‘Push to Pass,’ would have been enough time to allow Dixon to beat Pagenaud into Turn 2 on Lap 55. Dixon posted a slow time on Lap 55, but that was because he was stuck behind Pagenaud on Pagenaud’s out lap.

After completing the analysis, it’s evident that both Dixon and Pagenaud’s strategies were successful at giving them clear track to run on during the final cycle of pit stops at Long Beach. Dixon chose to pit one lap before the slower Helio Castroneves & Jack Hawksworth pair, while Pagenaud chose to pit two laps later. Over the course of the five laps in question, Dixon was 2.3 seconds faster than Castroneves. Pagenaud was 3.7 seconds faster than Castroneves and 1.4 seconds faster than Dixon. It took a miscommunication from Dixon’s pit and two impressive laps from Pagenaud allowed Pagenaud to jump Dixon during the pit stop cycle.

Kyle Brown