2015 NOLAMSP Pre Race Strategy Guide

Pit strategy can play a major role in determining who wins a race.  A conveniently timed yellow flag, when coupled with a well-timed pit stop, can vault a driver to the top of the running order.  On the flip side, a yellow flag that is poorly timed with a pit stop can ruin an otherwise great day.

This season I've been analyzing yellow flag and pit stop history at each track to see if trends exist in the timing and/or frequency of cautions.  If trends do exist, a clever strategist might be able to gain his/her driver a few extra positions on the track by pitting at the correct time.

This weekend will be IndyCar's first trip to NOLA Motorsports Park, so there aren't any past races to analyze.  That may not be much of a loss: my attempts to predict caution periods at St. Petersburg were not successful.  Instead of using data from NOLAMP, I 'borrowed' data from NOLAMP's sister track, Barber Motorsports Park.

Barber and NOLAMP were both designed by Alan Wilson, and a visual comparison of each track map seems to show some similarities.  Both have high speed first turns.  The tracks also feature multiple consecutive high speed right turns.  Barber's are at turns 2 through 4.  NOLAMP has two series of high speed right handers: turns 4 through 7, and turns 12 and 13.  Lastly, both have high speed chicanes, Barber at turns 9 and 10, and NOLAMP at turns 8 and 9.

There are some key differences.  Barber is quite hilly, while NOLAMP has no elevation changes.  IndyCar has also decided to slow cornering speeds by placing temporary curbing in the middle of what would otherwise be the racing line (seen in this onboard video of Juan Pablo Montoya).  This will force drivers to slow more for these corners, which should create more overtaking opportunities.

Caution Breakdown for Barber

Lap	2010	2011	2012	2013	2014
1		Yellow 1	Yellow 1		Yellow 1
2		Yellow 1	Yellow 1	Yellow 1	Yellow 1
3			Yellow 1	Yellow 1
4				Yellow 1
5				Yellow 1
6
7
8
9
10
11
12	Yellow 1
13	Yellow 1
14	Yellow 1
15
16
17
18
19
20
21					Yellow 2
22					Yellow 2
23					Yellow 2
24					Yellow 2
25					Yellow 2
26
27					Yellow 3
28					Yellow 3
29					Yellow 3
30
31					Yellow 4
32					Yellow 4
33
34
35
36
37		Yellow 2
38		Yellow 2
39		Yellow 2
40
41		Yellow 3
42		Yellow 3
43		Yellow 3
44		Yellow 3
45
46		Yellow 4
47		Yellow 4
48		Yellow 4
49
50
51
52
53
54
55
56
57
58		Yellow 5
59		Yellow 5
60		Yellow 5
61		Yellow 5
62
63
64		Yellow 6
65		Yellow 6
66		Yellow 6			Yellow 5
67		Yellow 6	Yellow 2		Yellow 5
68			Yellow 2		Yellow 5
69			Yellow 2		Yellow 5
70			Yellow 2
71			Yellow 2
72			Yellow 2
73			Yellow 2
74
75
76
77
78
79
80
81
82
83
84
85
86	Yellow 2
87	Yellow 2
88
89
90

The following laps were run under yellow in at least 50% of the races over the last 5 years:

• 1 and 2 
• 67

Based on this data, it might be beneficial for drivers to pit before the leaders start these laps.  A driver who pitted just before a yellow flag (and stayed on the lead lap) is likely to gain positions under the caution as other drivers make pit stops. 

I'm not convinced that there is something special about these laps that makes them more likely to be run under caution.  The list above may be a racing equivalent of the Wyatt Earp Effect - statistically, it's likely that a few laps will randomly happen to be run under yellow in multiple races.  This seemed to be the case during the last race at St. Petersburg.  Laps that had been run under caution in the past were not run under caution in 2015.

The one time of a race where it is easy to predict cautions is the first laps of a race.  Cars race in close proximity at the start of a race, and passing attempts are common.  Small mistakes are magnified as cars race wheel to wheel and drivers have less margin for error than they normally do because there are so many other cars nearby.  History at Barber supports this claim: 4 of 5 races had a caution on either lap 1 or 2.  I expect the same to happen at NOLAMP.

Lap Number of the Winner's Pit Stops*

Year	2012	2013	2014
Winner	Power	Hunter-Reay	Hunter-Reay
Stop 1	21	26	22
Stop 2	41	43	49
Stop 3	65	67	N/A**

*Each cell contains the lap number and track condition (green or yellow) for each of the winner's pit stops.

**The 2014 race at Barber was shortened by rain, so winner Ryan Hunter-Reay only made 2 pit stops.

In 2013, Will Power made his first pit stop on lap 31 while executing a 2 stop pit strategy that resulted in a 5th place finish.  During this run, there were only 4 laps of caution.  Power was the highest finishing car that used a 2 stop pit strategy.  Barber's many medium and high speed corners wear tires out, so lap times fall off significantly as a driver puts more laps on a set of tires.  Decreasing tire performance means that a 3 stop strategy is probably the way to go.

Cautions per Year

	2010	2011	2012	2013	2014
Total Cautions	2	6	2	1	5
Total Caution Laps	5	20	10	4	16
Average Caution Length (Laps)	2.5	3.3	5.0	4.0	3.2
First Caution Lap	1	1	13	20	76
Last Restart (Laps Remaining)	3	22	16	84	36

Caution Averages

	2010 to 2011 Avg	2012 to 2014 Avg	2010 to 2014 Avg
Total Cautions	4.0	2.7	3.2
Total Caution Laps	12.5	10.0	11.0
Average Caution Length (Laps)	2.9	4.1	3.6
First Caution Lap	1.0	36.3	22.2
Last Restart (Laps Remaining)	12.5	45.3	32.2

Like at St. Petersburg, the arrival of the DW12 in 2012 reduced the average number of cautions in races at Barber by over 1 per race, and this number is likely understated.  Wet races usually have more cautions than dry races, and the 2014 race started with a wet track.  The 5 cautions in 2014 were probably more than there would have been on a dry track.

Expect a caution on lap 1 or 2.  4 of 5 races at Barber have had a caution on the 1st or 2nd lap.

Strangely, even though an early caution is likely, cautions after the first 2 laps are relatively rare.  3 of the 5 races have had 2 or fewer cautions.

However, if a yellow flag is thrown in the middle of the race, others are very likely to follow.  5 of 11 cautions that occurred after lap 2 and had a restart (the race did not end under that caution) were followed by another caution within 3 laps.

The new aero kits add a new wrinkle to predicting cautions.  Unfortunately, the new aero kits did not hold up well at St. Petersburg.  Multiple cautions were thrown to collect debris from the track after cars hit each other, and a fan was seriously injured after being struck by a piece of debris.  IndyCar responded by mandating that both manufacturers strengthen their aero kits before this weekend's race at NOLAMP.  I believe that the amount of debris cautions will fall as the aero kits are strengthened and drivers learn that they cannot get away with as much contact as they could with the original DW12, although they probably won't return to 2012-2014 levels for a few more races.  I expect 4 yellows if the race is dry.

Rain

Of course, all this caution analysis could go out the window if it rains, and there's a 60% chance of rain on Sunday.  Drivers must adapt their driving styles if the track is wet.  First, drivers must adjust to a reduced grip level on track.  This means slowing earlier for a corner than they normally would.  Painted curbs, which some drivers drive over when racing in the dry, are notoriously slippery when wet, so drivers must adjust to avoid them.  Finally, drivers must change the path that they take through each corner.  Under dry conditions, there is a 'racing line' that all drivers try to follow because it is the fastest way around the track.  When a track is wet, the traditional racing line is often not the fastest way around the track.  The wet weather line can be quite different from the dry weather line, and drivers must learn where the wet weather line is during the race.  All these additional challenges provide drivers with many more opportunities to make mistakes, which increases the number of yellow flags in a race.

Strategists also face a unique set of decisions when rain is in the forecast, primarily because of the specialized tires that IndyCars use.  Dry weather tires, often called 'slicks', have no tread.  This gives the cars more grip when the track is dry, but can be disastrous if the track gets wet.  Slick tires can hydroplane at even very low speeds, so standing water on the track typically necessitates a switch to the treaded wet weather tires.  The treads on wet weather tires act like a pump to remove water from the area between the tire and the track surface, which eliminates the threat of hydroplaning in all but the worst of conditions.  The downside to wet weather tires is that they cannot be used when the track is dry.  Their soft rubber will easily overheat on a damp or dry track, causing performance to fall off dramatically.

Strategists must watch lap times and track conditions to determine the ideal time to switch between wet and dry weather tires.  After rain has stopped, there's an awkward period where the track is wet but drying.  As cars repeatedly drive over the same areas of the track, a 'dry line' of pavement forms.  Driving on the dry line is faster, but will severely degrade performance of wet weather tires.  Switching to dry weather tires will make a driver faster if (s)he stays exactly on the dry racing line, but dry tires are not without a downside.  The driver will struggle for grip if (s)he has to move off the racing line, either to pass another car or because of a mistake.

The strategists' and drivers' jobs will be further complicated because the track at NOLAMP does not dry evenly.  This will extend the awkward period where neither tire is ideal.  Drivers will be in for a challenge if some corners are completely dry while others have standing water.

Strategists have to listen to drivers complain about the tires they're using, and decide whether to listen to the driver or ignore his/her advice.  It's often a catch-22.  The driver will either complain that the wet tires are wearing out, or that the track is too wet for dry weather tires.  Trying to decide whether it will be better to 1) leave a driver out on wet tires when the track is drying but rain is expected to arrive at the track in 5 minutes, or 2) pit the driver now, switch to dry tires, and risk having to make another stop in a few laps is not an easy job.  Being on the ideal tire at any time can be worth multiple seconds a lap, so these decisions have real consequences for teams.  Being on the right tires for 2 more laps could easily be worth 5 seconds, a gap that could easily take 40 dry laps for a trailing driver to make up.

Since the time rewards of having the right strategy are so massive, look for drivers outside the top 10 to take big tire strategy gambles if there's rain in the area on Sunday.  If it's dry, expect a team to jump into the pits for rain tires at the first hint of moisture on the track.  If a wet track starts to dry, someone further back in the running order will change to red tires and try to make up for lost time.

If you want to get in touch, feel free to leave a comment or send an email to spottersstand@gmail.com.  Follow the blog on Twitter (@spotstandblog) for reminders about new posts.