In 2018, only three races were won by drivers starting outside of the top ten. Qualifying has always been recognized as a pivotal part of the race weekend as it is what sets drivers up for a good result on Sunday.
Using data from 2008-2018 which includes 187 races, I took a look at three interesting questions related to starting position and how races play out.
Question 1: Does your starting position impact your chances of winning?
Your starting position definitely impacts your probability of winning the race. Over 26% of race winners started on pole position. After pole position, I would consider there to be three distinct groups of win probability. Drivers who start in P2 and P3 both win around 12% of the time. Despite third position having a slightly higher probability than two, I wouldn’t consider that to be a trend but rather due to the sample size of 187 races which while large is still on the smaller end when it comes to something as rare as winning a race occurring.
Next up is the 4-5 group which each have between a 7 and 10 percent chance of winning the race. And finally, positions six and down have a fairly constant win percentage of around 0.5-3% depending on the number of cars in the race (lower percentage for Indianapolis for example as there are 33 cars). Looking at the graph, there are bumps along the way and some positions have a win percentage of zero, but it isn’t zero in reality. That is the historical win percentage from that position, which just means that no one has won from that position yet, but the probability of it happening isn’t actually zero. The smooth green line is a better estimate of win percentage for places six and down.
Win percentage is slightly higher from the top positions (1-5) on street and road courses than on ovals.
Question 2: How does average finishing position change by starting position and track?
The highest average finishing position (AFP) comes on road courses when starting on the pole, which yields an AFP of 4th place. Starting up high on road and street courses is more beneficial than doing so on ovals it appears. This is likely due to a combination of two things:
- it’s easier to pass on ovals than road/street courses
- there are more cars at Indianapolis than in any other race
Even after removing Indianapolis 500 races from the data, the trend of ovals having a worse AFP than road/street courses for the same starting position holds.
Road and street courses behave very similarly to each other, with road course starting positions yielding a 0.5 place better AFP on average for the first 10 places on the grid. After that, street courses have the advantage in AFP, showing that on street courses there might be more opportunities for poorly qualified cars to move up via avoiding accidents and pit strategy. Exploring this relationship more is something I would like to do in the future.
Question 3: Does where a driver qualifies impact their probability of finishing the race?
Excluding the starting position of 28th which has a low sample size (only 19 races started with at least 28 cars) starting on pole gives you the highest chance of finishing the race at an 88.8% chance. Not finishing the race includes crashes, mechanical failures, or anything else that causes you not to cross the finish line. From my exploring of the data, mechanical failures are essentially random and not related to starting position, so the differences between each position’s finishing percentage can be described as a proxy for the probability of getting caught up in or causing a crash.
The green line shows a smooth curve that slowly decreases as you head back on the grid. Positions after 25 shouldn’t be viewed as fully accurate percentages because of the smaller sample size for those starting places, but rather just a general trend of what to expect from that place.
The analysis confirms what many people would guess: if you start up front, you have less cars to deal with, less of a chance of getting mixed up in an accident, and a higher probability of finishing the race.
There is no disputing that starting position is important when it comes to race performance. It keeps you out of trouble the higher you are up the grid and close to 70% of race winners start the day in the top five. Road and street course qualifying is slightly more important than oval qualifying as there are more opportunities to move up throughout an oval race. If you have any more starting position questions you’d like answered reach out to me on Twitter!