That is by comparison with his records on hardcourt and grass. Of his 24 titles: 20 are on hardcourt including one Grand Slam and 8 Masters. 3 are on grass including one biggie, the Olympic gold medal. 1 is on the now defunct carpet. Clay titles = 0. Best showings on clay to date are 4 semi-finals: 1 at the FO (2011), 2 at Monte Carlo (2009 & 2011) and 1 at Rome (2011). 2011 was obviously his best year so far on clay but looks to have regressed in 2012 and seems no nearer picking up a title on one of the game's 3 most important surfaces. Considering he spent 7 of his formative years training on the clay courts of Spain, this is really surprising. Just why cannot he perform as well on it? Thoughts (serious ones please)?