By Andrew Benson
Juan Pablo Montoya and Kimi Raikkonen may be rueing the bad luck that helped take Michael Schumacher to the brink of another Formula One title at the US Grand Prix.
Schumacher's title challenge has been boosted by others' mistakes
But their hopes of winning the 2003 world championship were not doused by the rain and cold winds of Indianapolis, they were slowly strangled by a series of errors through the year.
Those mistakes prove that for all the impressive progress made by Williams and McLaren this season, they are still some way short of the standards set by Schumacher and Ferrari in recent years.
BBC Sport looks back at the decisive moments in a topsy-turvy F1 season.
Australian Grand Prix
Montoya spun away victory in the first race of the season
Melbourne, 9 Mar
Juan Pablo Montoya spins out of the lead with just 10 laps to go, handing victory to David Coulthard. The Williams driver recovers to finish second, ahead of Kimi Raikkonen and Michael Schumacher.
Points squandered: Montoya - two.
Austrian Grand Prix
A1-Ring, 18 May
Montoya's Williams-BMW suffers an engine failure while he is leading the race from Schumacher and Raikkonen.
The Colombian would probably not have beaten Schumacher's Ferrari, but a sure second place goes up in smoke.
Points squandered: Montoya - eight.
Canadian Grand Prix
Ferrari should have been beaten by Williams in Montreal
Montreal, 15 June
Either Williams driver could and should have won the race, but both threw it away.
Montoya spun out of second place at the end of lap one, promoting Michael Schumacher into a position whereby he could challenge brother Ralf for the lead.
Ralf then lost time at the first pit stop and Michael grabbed his chance, demoting Ralf and Montoya to second and third places.
Points squandered: Montoya - between six and eight. The Colombian's spin lost him either two or four points depending on whether he could have beaten Ralf Schumacher. Thanks to the Williams drivers' errors, Michael Schumacher also got four more points than he should have.
European Grand Prix
Raikkonen sits by the side of the track after his engine failure
Nurburgring, 29 Jun
Kimi Raikkonen dominated the race from pole position in his McLaren before an engine failure put him out of the race.
Points squandered: Raikkonen - 11. That's 10 points for the win, and one point gained by Michael Schumacher for promotion from sixth to fifth as a result of the Finn's retirement.
Hungarian Grand Prix
Hungaroring, 24 Aug
Montoya admits he eased off after the first sector of his qualifying lap to ensure he made no mistakes. It is a crucial misjudgement.
Starting from fourth on the grid when he could easily have been higher, the Colombian's Williams gets away slowly on the dirty side of the track and drops right down the field.
Montoya recovers to finish third behind Fernando Alonso and Kimi Raikkonen in a car that was fast enough to battle for victory.
Points squandered: Montoya - a minimum of two, possibly four
Italian Grand Prix
Schumacher grabbed victory at Monza from under Montoya's nose
Monza, 14 Sep
Montoya makes an error on his qualifying lap that allows Schumacher to steal pole position by 0.051secs.
On top of that, Williams choose to run the car with too much downforce in the race, which harms Montoya's top speed.
That means he cannot challenge Schumacher for the lead.
Points squandered: Montoya - four. Two for the lost victory and two gained by Schumacher as a result.
Total points lost through mistakes:
Montoya - A conservative estimate of 22, but possibly as much as 26.
Raikkonen - 11
Without these - and admittedly not taking into account the fact that Schumacher made mistakes of his own early in the season - Montoya would already be champion and Raikkonen would be one point ahead of Schumacher in the battle for second place.