The world rankings system explained
Lee Westwood's calf injury will not only cause the 37-year-old Briton to miss this week's Portugal Masters but it will lay the world number two low for the rest of the month.
The huge consolation for Westwood, however, is that he could end Tiger Woods' 270-week run atop the official world golf rankings on October 31 without hitting a ball in anger.
Flame-haired Englishman Ian Barker is perhaps best placed to explain how players rise or fall in the rankings. The 47-year-old calculates rankings points won and lost and admits that, while the system is complicated, there is method in the madness.
"It's true the world ranking system - we're talking nine tours, 11 at the start of next year - is necessarily complicated," said the Wentworth-based Barker, who has been with the European PGA Tour for nearly 24 years. "But it shouldn't be baffling."
Barker said the world rankings differed from the way the PGA Tour money list and Race to Dubai were calculated.
"Those are very simple in that every player is set to zero at the beginning of each season. The more you win the higher up the list you go and then everything is back to zero for the next season.
"The world rankings are constant, they never go back to zero. So a system was devised, over a two-year period, where players lose points as well as gain them.
"The amount of points awarded for each event varies -- the stronger the field the more points on offer, with a maximum of 100 for a major.
"So players have those points in the bag. Then over a two-year period they will gradually lose most of them or have them whittled down. For instance, points won two years ago are virtually lost. The highest weighting is points won over the last three months."
Barker said movements in the rankings were determined by players losing more points than others over a two-year period and their current form.
"Tiger has had more to lose over the last two years than anyone else. And then he took his break, of course," added Barker.
"If Lee doesn't play for the rest of this month his average points will be higher than Tiger's on October 31. Woods will lose more points than him over the next three weeks."
However, that relatively 'straightforward' scenario is under threat thanks to the brilliant recent form of Germany's Martin Kaymer.
"Martin has won more world ranking points than anyone this year. If he finishes in the top two at Valderrama (Andalucia Masters) on October 31, and I know he's entered while Lee hasn't, his points average will be better than Lee's and he will be number one."
Barker said Woods's reign at the top of the rankings could have ended at the hands of Phil Mickelson but the left-hander failed to take his opportunities.
"Phil Mickelson has had 12 chances to go past Woods since the US Open but missed them all," added Barker. "His recent form hasn't been that good, so Lee has become favourite to overtake Woods."
All signs point to a thrilling end to the year.
"It's set up a real 'Clash of the Titans at the WGC Champions tournament in Shanghai," he added.
"Westwood, Kaymer, Woods and Mickelson are all playing and all could be number one on November 7. And then on to the Dubai World Championship.
"As each week progresses the world rankings are in Westwood and Kaymer's favour. I wouldn't be at all surprised to see a European one-two come December 31."