Both players won their first major titles - McDowell at the US Open, Kaymer at the US PGA - both won four times and both were members of the victorious Ryder Cup side.
It was the 25-year-old German who took the "Race to Dubai" money list title, but against that McDowell was, of course, the match-winning hero against the Americans at Celtic Manor in October.
A judging panel of writers and commentators debated the many merits of the pair, but when it came to the vote the result was split right down the middle.
There has never been a season quite like it for the European Tour, with South African Louis Oosthuizen becoming Open champion at St Andrews, Lee Westwood taking over from Tiger Woods as world No 1 and Ian Poulter, Ernie Els and Francesco Molinari all winning World Golf Championship events.
McDowell, who on Sunday beat Tiger Woods in a play-off in America, commented: "I am truly humbled to accept this coveted award.
"It is the icing on the cake on what has been a very special year for myself, Martin and everyone involved in European golf.
"It is an honour to share this award with a player of Martin's calibre. He is one of the best players of our generation and I am sure will enjoy many more successes in the years to come.
"I achieved many of my dreams this season and feel fortunate to have enjoyed some very special moments. However, the highlight of the year for me was being a part of the winning European Ryder Cup team.
"There is nothing quite like the atmosphere of the Ryder Cup and the experience of playing for both your team-mates and the European fans under the most extreme pressure. I hope that I am lucky enough to play in many more successful teams in the future."
Kaymer said: "This has been a truly great year for me and winning this award is the perfect ending.
"It is recognition for my performances in 2010 and to be voted for by the golfing media, the people who watch and report on our sport throughout the year, makes me feel very proud.
"I am always trying to follow in Bernhard Langer's footsteps and to see that I have now won an award that he was the first to win back in 1985 is very satisfying indeed. But he is still many steps ahead of me!
"Graeme deserves this recognition as much as I do.His winning match in the Ryder Cup was huge for all of Europe and for both of us to now make history in terms of sharing this award for the first time represents a very proud moment for both our families and also shows how strong European golf is right now."