Valentino Rossi will start his 100th MotoGP race for Yamaha this weekend at Estoril.
After leaving Honda at the end of 2003, the Italian shocked MotoGP with a stunning victory on his M1 race debut in the 2004 season-opening Africa's Grand Prix.
Rossi went on to win the world championship for Yamaha in both 2004 and 2005, before losing out on the 2006 title to Nicky Hayden at the very final round - then slipping to a MotoGP worst of third during the first season of 800cc racing in 2007.
The Italian superstar fought back to claim his third Yamaha title in 2008 and is on course for a fourth in 2009, holding a 30 point lead over team-mate Jorge Lorenzo with four rounds to go.
Prior to joining Yamaha, Rossi won three premier-class titles for Honda - the last 500cc crown in 2001, then the first two 990cc MotoGP titles in 2002 and 2003.
During his 99 Yamaha starts to date, Rossi has taken 44 wins (including six in 2009), 71 podiums and 27 pole positions.
Rossi's most successful Yamaha season, in terms of race wins, was in 2005 when he matched his Honda record of 11 victories in one season.
As well as his six premier-class titles, Rossi won the 250cc championship in 1999 and the 125cc title in 1997, both with Aprilia.
Rossi made 64 race starts for Honda between 2000 and 2003, winning 33 times, and 60 starts for Aprilia between 1996 and 1999 (in 125 and 250) when he took 26 wins.
The following list shows the riders who have made most starts in the premier-class riding Yamaha machinery:
1. Norick Abe 143
2. Carlos Checa 112
3. Valentino Rossi 99
4. Christian Sarron 98
5. Eddie Lawson 86