Why Hamilton lost out to George in Miami and Tyre Degradation Analysis
George ran an offset strategy with Hard compound and got lucky safety car pit stop
How are Formula1 tyres different?
Formula 1 tyres are one of the most important pieces of equipment in a race car. They provide traction, braking, cornering grip and handling to the car to help drivers navigate their way around a track as quickly as possible. The tyres are also responsible for transferring the power from the engine to the ground.
There are three different types of tyre compounds that can be used in Formula 1: hard, medium and soft. The harder the compound, the longer it will last but it will have less grip. The softer compound will have more grip but it won’t last as long. Teams usually use two or three different compounds during a race weekend depending on track conditions and how they want their car to perform. The tyre pressure is also an important factor when it comes to Formula 1 tyres . Too much pressure can cause them to overheat and blister while too little pressure can make them too soft which will affect their performance on track.
Why Formula1 tyres degrade so fast?
The tyres used in Formula 1 racing are much different than those found on regular passenger cars. They are made from very soft rubber compounds that offer good traction but wear out quickly. To compensate for this, teams use special tyre strategies during races to ensure they have enough fresh tyres available at the end of the race.
One thing that makes Formula 1 tyres so unique is their ability to heat up and cool down quickly. This is due to the fact that they operate at such high temperatures for extended periods of time. When new, they can reach temperatures close to 200 degrees Celsius, which is why it’s so important for teams to manage their tyre usage during races.
Formula1 Tyre Degradation profile:
How quick is the medium tyre compared to hard?
To find out the pace difference, I started out with taking the lap times of all drivers on stint 1. Interestingly the only drivers starting on the Hard compounds are the ones that are misplaced relative to their car pace. We had Russell, Ocon, Stroll, Vettel and Latifi. Everyone else in on Medium compound tires.
The inner chart shows a scatter plot which Tyre Life on x-axis and Lap Time on y-axis. Tyre Life is not always equal to the Lap Number, some times Teams maynot have fresh tyres for the race in which case they use scrubbed/old qualification tyres. Yellow dots represent medium compound tyres, whereas white dots represent Hard compound tyres.
There are several elements that factor into setting different Lap Time, from tyres, fuel load, aero, car setup, engine, traffic and more.
Now, I fit a linear regression plot of order 2 for both compounds represented as lines in different colors along with a confidence interval. Notice how as the medium tyre wears off the laptimes shoot up.
It is no surprise why most teams pitted before the medium tire line crosses the hard one, to improve performance by switching to the fastest compound.
Histogram plots above and on the right of the chart shows the count value in each bin.
Why Hamilton lost out to George in Miami?
George was mighty through out the weekend with a P2 in Free Practice 1 and P1 in FP2 on Friday. As it turns out Mercedes is trying to find solutions to porpoising issues and they had to run in higher speeds/ low fuel load to get the data. During the race, George lost positions as the hard tyres took their time to get to temperature, but a lucky safety car at the right time helped him to switch to fresh mediums, which from the above chart have a window of about 20 laps, enough to finish the race.
The above plot is self explanatory, as Hamilton switched to hards after 20th lap the advantage gained from faster mediums is lost but not completely since Russell has to change tyre later on. As the Russell hards wore out and Hamilton’s hards were in right temperature to gain valuable pace. Lucky safety car around 40th lap gave a free stop to George and bunched up the field. As we know the fresh mediums are almost a second quicker the delta started to reduce and eventually finished P5. Only driver to score in top 5 positions for this season.
Colors tested with user inputs, for all color vision deficiencies- Protanopia, deuteranopia. If you have Tritanopia, please let me know if you find it difficult to differentiate hards and mediums in the scatter plot. With simulated colors, it was close, I’ll update colors to make it accessible.
Please leave your feedback in the comments. Let me know if you have new ideas, or want to know anything particular about formula1.
What was your justification for using a second order regression?
Please leave your feedback here. Let me know if you have new ideas, or want to know anything particular about formula1.