A fantastic article was published earlier this week by BBC’s technical analyst Gary Anderson. See it here: http://www.bbc.co.uk/sport/0/formula1/18669094
In it, he posits that Button’s smooth driving style does not generate the requisite heat in the Pirelli tires and also requires them to be used in a way that they are not comfortable with. Let me do a bit of summary first so we can discuss this with greater accuracy.
Most drivers, including Hamilton, approach corners in a straight line, break in a straight line and then turn in with very little to no breaking pressure. Most likely, they use a little bit of throttle to stabilize the rear end. Button, however, will break past the turn in point and will only really get on the power closer to the apex.
This style makes several demands. Button must turn in earlier than Hamilton, he probably runs a more rearward break bias than Hamilton and he must have a wonderfully balanced car to give him confidence that the will not have uncontrollable oversteer or excessive understeer under breaking. When the whole thing works, Button will carry more speed into the corner than Hamilton and that advantage into the corner will match Hamilton having more time on the loud pedal.
A slight tangent here. Button’s style is likely derived from his karting days, specifically before he was in shifter karts. All sprint karts, the kinds that F1 drivers start out on when they are 2, only have one break disc on a live rear axle. The kart has similar driving characteristics to Mustangs (sorry bout that) where if the inside rear wheel is on the ground it will push the whole car wide unless judicious throttle brings the rear around into oversteer. Since karts have no suspension, however, the inside rear wheel is lifted caused by the load transferring onto the outside front wheel. To make sure the load is sufficient, karting drivers will break as deep as possible and turn in a little early and carry the breaking to the apex, grabbing throttle only at the apex for fear of putting the inside rear back onto the ground.
Modern F1 cars like most road cars, however, have differentials which removes the inside rear wheel issue and allows Hamilton’s break and turn in strategy.
Because Button is more gentle on his breaks than Hamilton, he does not generate adequate heat in the fronts thus leading to understeer when he turns in. This is a very tricky issue. Either Button changes his style to suit or he has to find a more aggressive front end set up that would generate the heat for him.
Anderson makes a further point that is also very interesting. He claims that Alonso uses much the same tactic as Button. Alonso has adapted, however, and Button has not. Well there is no doubt that Button has not adapted but I do not think that Button’s and Alonso’s styles are completely analogous.
If you look carefully at Alonso’s onboard laps, you see him very aggressively turning into corners almost intentionally generating understeer to scrub speed. Maldonado uses a similar tactic. This generates front tire heat in a way that Button never does. Alonso’s tactics are also not an adaptation. Look at this video of Former BBC commentator Martin Brundel examining various driving styles.