By Andrew Benson
On the face of it, the motorsport year had a somewhat familiar feel to it in 2003, with Ferrari's Michael Schumacher and Valentino Rossi of Honda winning the blue-riband events in cars and bikes.
But in reality it was a year of contrasting changes.
In stark contrast to 2002, Schumacher faced a real fight this season, even if the brilliant German did eventually clinch an all-time record sixth world Formula One drivers' title.
Schumacher may have won at least three times as many races as anyone else, but he came very close to losing the title in the face of a reinvigorated challenge from Williams and McLaren.
At the same time, there were signs that Schumacher's utter domination may be beginning to fade - he made more mistakes and looked less convincing more often than for a long time.
Challenging his position at the pinnacle of F1 are three sparkling young talents.
McLaren driver Kimi Raikkonen was ice-cool and relentless in keeping his hopes alive while driving a car that was not quite at the cutting edge of pace.
Juan Pablo Montoya, who will join Raikkonen at McLaren in 2005, is a more mercurial talent, but his raw aggression also allowed him to take Schumacher to the limit.
Potentially even better than either of them is Fernando Alonso, who showed many of the attributes of the young Schumacher while marking himself out as a future champion in his first season at Renault.
World rallying witnessed an even bigger change.
Peugeot, who were expected to be the team to beat for a fourth successive year, found themselves eating the dust of new-boys Citroen, as well as struggling to keep up with revised cars from Subaru and Ford.
Four drivers went into the final round with a chance of the title, although Peugeot's Richard Burns dropped out before the event with what turned out to be a brain tumour that will keep him out of the series in 2004.
That left Petter Solberg of Subaru in a battle with Citroen's Sebastien Loeb and Carlos Sainz; Solberg prevailed when Citroen decided the manufacturers' title was of more value to them than the drivers' championship.
In bike racing's equivalent of F1, Valentino Rossi also had to face more of a challenge than usual, although the Italian found it rather easier in the final analysis to fend off fellow Honda rider Sete Gibernau than Schumacher did his pursuers.
But while Schumacher's desire to dominate F1 with Ferrari seems to be unquenchable, Rossi has decided to ring the changes for 2004 in search of a new challenge.
Echoing Schumacher's move to a then-struggling Ferrari in 1996, Rossi has for next year left Honda in favour of Yamaha, who have not won the title since 1992.
Meanwhile, MotoGP continued to suck the life out of its former rival World Superbikes, with 2003 Superbike champion Neil Hodgson becoming the latest in a long line of top riders to switch to the higher level after finally clinching a title he has waited a long time to win.
Whether Superbikes will be able to survive in any form other than as a feeder series remains in serious doubt.