How and why have overtaking rates changed in F1?

For most of its history, F1 has been known as a series where overtaking is difficult. The reasons for this are complex, but are often boiled down to the difficulty of following another car closely enough. Here we look at how overtaking numbers in F1 have changed over the past few decades, he reasons for it and whether overtaking is some that should be actively encouraged within F1 regulations.

What counts as an overtake?

There are several sources of overtaking numbers in F1, but unfortunately they disagree about the number of overtakes in almost every race. This is because it is not always clear what counts as an overtake. Overtakes caused by retirements and changes of order on lap 1 generally do not count, but what about a driver tumbling down the order due to a broken front wing? What about a car that overtakes, only to be quickly repassed? Or what about a situation where 3 drivers are jostling for position? Then there’s the fact that there is so little data on historical races. It gets complicated quickly. Below we see overtaking data taken from reddit.

Fig 1: Overtakes per season

This shows the total number of overtakes in each season. However, F1 seasons how expanded during this time, from around 16 per season, to the 20+ reasons that are regular today. For this reason, it may make more sense to present the data as overtakes per race. This reduces the peak a little, but the general trends remain similar.

Fig 2: Overtakes per race

One way to check the reliability of this data is to compare with another source. An Autosport article, presents significantly different numbers for each year (for example, 821 overtakes in 2011 instead of 1,249). However, if we care about trends rather than specific numbers, we can calibrate the results relative to a specific year (in this case 2000 was arbitrarily chosen) to see whether the sources agree on how overtakes vary each year.

Fig 3: Comparison of 2 sources of data to check reliability

This graph shows that these 2 sources actually agree very well with each other to show trends over time. As the two sources do not fully overlap, analysis of the early 90s will be exclusively from Autosport, whereas the most recent years will be from the Reddit data.

1990-1994

The years 1990-1993 can be seen on the comparison graph above, and clearly have significantly more overtakes than subsequent years. Whilst it may be tempting to attribute this to driver changes (Prost, Senna, Mansell and Piquet all stopped racing during this period, excluding a couple of brief Mansell cameos), the more likely explanation is in regulation changes. The two biggest regulation changes for 1994 were the introduction of refuelling, and the increased safety standards following Senna’s and Ratzenberger’s deaths at Imola that year. Either one of these could have had an effect, but refuelling is the most likely explanation. This factor is not often talked about when discussing overtaking, but the logic is there. In the days of refuelling, a car would typically be fastest just before a pit stop. If it came out of the pits behind another (theoretically slower) car, its increased weight from the fuel would usually have a greater effect than the benefit of having fresher tyres. After refuelling was banned, a car that has stopped for fresh tyres (usually) has an inherent pace advantage on one that has not, making overtakes easier. Refuelling also limits strategy more, and a driver who knows he has more fuel would be more likely to wait for a rival in front to pit before passing them in the pit window.

1994-2009

Fig 4: Overtaking rates when refuelling was allowed (Reddit data)

This zoomed in graph shows the yearly variations better. Although the data looks relatively flat (and erratic!) for much of this period, there is a steady upwards trend over time. The major discrepancy to this trend is in 2005. This is explained by a rule which stipulated that tyres could not be changed during the race, meaning that significant differences in tyre life were impossible. Naturally this lead to a reduced ability (and desire) to overtake cars on track. It also lead to the disastrous US GP, where only 6 cars started the race, further negatively impacting the number of overtakes.

2009 is also worthy exploring, given the number of overtakes is below average for the era, despite new aerodynamic rules being implemented that were specifically designed to increase overtaking. It is something of an oddity. Other than the aerodynamic changes, slick tyres were also introduced. However this cannot explain the lack of progress either, as the 1998 season introduced grooved tyres without a significant change in overtaking rates. So why did overtaking rates go down when they were designed to go up? Perhaps the development of the double diffuser (a clever rule loophole exploited by several teams) reduced the positive effect of the new rules. Another potential explanation is that the season was exceptionally competitive. Force India had the worst car that year, but still managed a pole and second place finish (almost a victory) on merit. If the fielder is closer, it is logically harder to be significantly faster than other drivers in a race.

Upwards Spike

There is a very obvious upwards trend in numbers of overtakes between 2009 and 2011 (clearly shown in Fig 1, Fig 2 and Fig 3). The regulations were mostly the same for 2010 compared to 2009, with a few notable changes, Firstly, KERS was banned, which should have lead to fewer overtakes (many overtakes in 2009 were due to one car having an electric power boost and the other one not having it). Secondly, the double diffuser was banned, which may have had a positive effect in bringing the cars back to what was actually envisioned for 2009 rule changes. Finally, refuelling was banned once again. As in 1994, we see a significant change in overtaking numbers when refuelling rules change, which confirms that it is an important factor. Overtakes in 2010 were at their highest level in almost 2 decades. Given this, it is worth questioning whether further changes to encourage overtaking were really necessary. Nevertheless, F1 introduced DRS and Pirelli tyres for 2011.

These changes were successful, putting overtaking rates at their highest rate ever recorded. Subsequent years saw overtaking rates fall (although still remain very high). This could be due to DRS zones being better optimised, but it probably more likely due to Pirelli becoming more conservative with their tyres. Other factors like the wider cars introduced in 2017 may also be partly responsible for the general downwards trend observed today (but note again that overtakes did not increase in 1998 when the narrower cars were first introduced).

It is worth pointing out how difficult it is to properly compare overtaking rates season by season. Factors such as number of cars in a grand prix, reliability rates, grid penalties, circuits raced on and number of wet races vary year to year and can be difficult to account for. It can be difficult to separate random yearly variations from all of these factors.

Should overtaking be encouraged?

When grooved tyres were introduced in 1998, it was suggested that it could lead to more overtaking due to longer braking differences and greater ability to run off-line (as mechanical grip had less of an impact). When slick tyres were reintroduced, it was also suggested that that it could lead to more overtaking due to the increased importance of mechanical grip, meaning that the dirty air effect may be smaller. This example, along with the failure of the 2009 regulations to increase overtaking, suggests that even experts and rule makers do not have a good understanding of how to authentically increase overtaking, leading to more artificial solutions such as DRS or the proposed (and subsequently rejected) reverse grid qualifying.

It is valid to ask whether more overtaking is actually good for the sport. Whilst more overtaking seems like it would increase entertainment, there is a logic to keeping the absolute number of overtakes lower to increase the value of each one. To compare with other sports, a goal in football (soccer) elicits far more excitement than a basket in basketball, because it is rarer and more valuable. If overtaking becomes too easy, then it negatively impacts other aspects of the sport such as defensive driving, strategy calls and the chance for unexpected results. In F1, a common complaint of DRS is that the overtakes are not as impressive or entertaining as overtakes without the system. On the other hand, it is extraordinarily rare in modern F1 to see overtakes without either DRS or a significant tyre advantage, which suggests that something at least partially artificial may be required. F1 is fundamentally a sport, but must consider business and entertainment value too.

One thing that is clear is that there is no direct correlation between the number of overtakes and the amount of entertainment. Nobody realistically suggests that the 2010s was 2-3 times more entertaining than the 2000s because there were so many more overtakes! Currently, many fans reminisce fondly of the 1990s and 2000s, a time when overtakes were at an all time low. Whilst overtaking is rarely brought up as a reason why this era is well loved, it does serve as a reminder that more is not always better.

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