Number Crunching: How Much Of A Factor Is Weight In MotoGP?
The debate has been rumbling under the surface for some time, but at Jerez it finally burst to the surface. It emerged that Marco Simoncelli and Valentino Rossi had submitted an informal proposal to the Safety Commission to examine having a combined minimum weight for both bike and rider in MotoGP, just as there currently is in the 125cc class. Their argument was that lighter riders had an unfair advantage, and that by setting a minimum weight, the larger riders would have a better chance of competing.
The main advantage, it was said, was one of fuel consumption, especially since the introduction of the 800cc bikes, which also saw the fuel limit reduced to just 21 liters. Nicky Hayden related that while he was at Honda, his was forced to run a much leaner setup than his erstwhile teammate, Dani Pedrosa. Rossi agreed with Hayden's assessment, but admitted that taller riders did have more leverage over the machines.
On the other side of the argument, Dani Pedrosa dismissed it altogether, saying this debate had dogged him since he had entered the class. He pointed out that when he first switched to MotoGP, many fans and journalists had said he would never be able to manage the heavier and more powerful machines. Now he was winning regularly, the arguments had been turned on their head, and what was previously flagged as a weakness was now being hailed as an unfair advantage. Pedrosa put the complaints down to the universal human mistake, thinking the grass is greener on the other side of the fence. If Simoncelli and Rossi thought that Pedrosa had an advantage, he said, "they should try being small."
The debate made us curious, and thanks to some solid legwork from a loyal forum visitor, it is possible to test the hypothesis that smaller and lighter riders have an unfair advantage over taller and heavier ones by examining the weights and heights of all of the current riders in the MotoGP class, and comparing them to their results. Below is a table containing all of the weights and heights (as listed on the official MotoGP.com website) of all of the current MotoGP riders, along with Chris Vermeulen, as the only other rider to have won an 800cc MotoGP race. The table shows the average height (171.7 centimeters) and average weight (62.6 kilograms) for all of the riders currently in the class (plus Vermeulen), as well as the deviation above or below the mean for each rider, and the standard deviation (SD) for both height and weight.
|SD||Deviation||Weight (Kg)||Rider||Rider||Height (cm)||Deviation||SD|
|Mean Weight||62.6||Mean Height||171.7|
|Standard Deviation (kg)||6.8||Standard Deviation (cm)||7.1|
So given the weights and heights, we can calculate whether the number of victories bears out the hypothesis that lighter riders are at an advantage over the heavier riders. If lighter riders have a significant advantage, then surely they would have more victories than the heavier riders? And given the claim that the effect has been magnified by the 800cc machines and their frugal fuel limits, there should be a clear pattern to the results during the 800cc era.
Based on the table above, we can divide the riders who have won a MotoGP race into two groups: those who are heavier than the average of 62.6 kg, and those who are lighter. Just 7 riders have won a MotoGP race since the class moved to the 800cc formula, from a total of 73 races held. Four riders have taken victory who fall into the "light" category: Casey Stoner, Dani Pedrosa, Loris Capirossi and Andrea Dovizioso; while three riders from the "heavy" have won races: Valentino Rossi, Jorge Lorenzo and Chris Vermeulen.
Adding the numbers of victories to the rider names gives us the following table:
|"Light" riders||Victories||"Heavy" riders||Victories|
|Casey Stoner||24||Chris Vermeulen||1|
|Loris Capirossi||1||Valentino Rossi||21|
|Dani Pedrosa||10||Jorge Lorenzo||15|
It would appear, then, that the two categories of riders are evenly balanced, with the heavier riders taking a single victory more than the lighter riders. Going on to look at championships gives a similar picture, with three of the four 800cc titles going to heavier riders (Valentino Rossi and Jorge Lorenzo) and just a single championship going to a lighter rider (Casey Stoner). See the championship table below:
|"Light" riders||Championships||"Heavy" riders||Championships|
|Casey Stoner||1||Valentino Rossi||2|
There was much debate after the Jerez race, with fans on both sides of the argument drawing conclusions from the race to bolster their own case. But the raw numbers above appear to show no correlation at all between rider weight and rider success, with flyweight Toni Elias having just as many 800cc victories as man mountain Marco Simoncelli. Looking at the list of winners, there is only one common factor shared among them, and weight is certainly not one of them. Only four riders have won more than one 800cc MotoGP race, with Capirossi, Vermeulen and Dovizioso all taking victory in either wet or very mixed conditions.
Stoner, Rossi, Lorenzo and Pedrosa have the vast bulk of wins between them, taking victory 70 times out of the 73 contested races. And of that foursome, the spoils are split fairly evenly, with lightweights Stoner and Pedrosa sharing victory 34 times against 36 victories for Rossi and Lorenzo.
The only correlation here is talent, and the ability to ride an 800cc MotoGP machine at the very limit for a 120km race. Weight and height would seem to be as relevant to victory as hair color or favorite soccer team, an unrelated and non-causal factor. To win, you just have to work harder, be in better shape and have more talent than your rivals, and though taking a second pass at the dessert trolley is probably inadvisable, this has more to do with the effect of cake on your fitness levels than on your actual ability to ride fast. More weight may affect your fuel consumption, but going by the numbers, the advantages in terms of bike setup and corner speed probably outweigh the minor benefit of using less fuel. What the numbers show is that talent, not kilograms, determine your success aboard a MotoGP machine.