The circuit was criticised by drivers for its lack of overtaking opportunities. Changes in Formula One in 2011, including the introduction of the Drag Reduction System and the switch to Pirelli tyres, partially improved that with 27 passes recorded in that year's race, 22 of which were accredited to the assistance of DRS. However, the five 'normal' overtakes still represented the year's second lowest total, although the adoption of two DRS zones for that year's race limited the potential for non-DRS assisted passes. Despite this, the 2012 race was shown to have many different overtakes and became one of the most thrilling races of the season. It also had many more retirements – a total in four in 2012 compared to zero retirements during the 2011 race.