Valentino Rossi has mentioned Casey Stoner, followed by Gibernau as his hardest rivals ever. Gibernau was known for his wet-weather abilities and was occasionally referred to as "Rainmaster". However, despite his flair, he was all too often let down by an apparently temperamental nature. In-race setbacks could disproportionately affect his competitiveness, both negatively and positively. His career started slowly until he found his motivation and his intermittent flair became consistent. Then he was the principal challenger for Rossi's crown until 2005. The 2006 brought a series of emotional, technical, and injury setbacks, apparently sapping his motivation. It culminated in a major mid-season no-fault racing incident which effectively eliminated him from the championship.