McDowell will finish top of the Race to Dubai rankings if he wins the tournament and if he is second on his own USPGA champion Kaymer would have to be third to win the Order of Merit.
If McDowell comes third, Kaymer has to be in the top 20 while anything worse than that and the Northern Irishman cannot catch his Ryder Cup team-mate.
The Dubai World Championship will be McDowell's fifth consecutive appearance on the tour and in that time he has slowly chipped away at Kaymer's lead at the top of the money list.
"I started off this five-week run with Martin nearly a million euro ahead of me and I wasn't quite sure I would be able to catch him," added McDowell.
"I wanted to get here with an opportunity to win the Race to Dubai and I've given myself that chance now. I am excited about it and trying to put a bit of polish on a good season.
Race to Dubai too close to call - Westwood
"I've been feeling great and feeling like there is plenty left in the tank. I'm probably feeling as good about my game right now as I have at any point during the season."
Kaymer, who skipped the Hong Kong Open to rest ahead of the Dubai tournament, called this week "the biggest of my career so far" and said winning would complete three goals he set for himself - to win a
and become the number one golfer in Europe.
"So two-thirds are done and hopefully this week I can win the Race To Dubai and become the number one in Europe," said the 25-year-old.
"So then I have done everything in one year, it would be fantastic. I don't need to win but that is my goal.
"I can't rely on Graeme playing bad. He's been playing great golf in the last few weeks."
Meanwhile, Rory McIlroy has delivered a fresh snub to the PGA Tour after
quitting the US circuit
earlier this month.
The world number 10 from Northern Ireland said he may not play the tournament dubbed the unofficial 'fifth major'.
The 21-year-old explained that he was not a fan of the TPC Sawgrass layout in Florida and was considering dropping the Players Championship from his 2011 schedule.
"I don't like the course, that's one of the reasons I'm undecided whether to play it or not," he added.
"That's not to say the 'Players' isn't a great event, it's very prestigious and it would be great to win it one day but it just might not suit my schedule next year."
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