A two-time Olympic gold medallist, 12-time major marathon winner, world record-holder - Eliud Kipchoge still has something to prove.

"I think Boston is a game-changer for me," the world's greatest marathoner said as he prepared for his debut in the world's most prestigious road race.

"Boston is the oldest marathon ever, and I think actually any serious marathoner should put his or her own feet once - if not a lot in their life - on the Boston streets."

A 38-year-old Kenyan who has been collecting marathon victories since 2013, Kipchoge will make his Boston Marathon debut on Monday in the 127th edition of one of the world's greatest races.

A victory would give him wins in an unprecedented five of the six major marathons.

Kipchoge also has run the two fastest marathons ever, and four of the top six, breaking his own world record in September at Berlin with a time of 2 hours, one minute, nine seconds. He also owns the course records in London and Tokyo.

That doesn't even count the 1:59:40 he ran in 2019 in an exhibition in a Vienna park - the only runner ever to break 2 hours at the 42km distance. The time does not qualify for a world record because it was run with pace-setters and other assistance that would not be allowed in an actual competition.

Even so, there has always been a sentiment among runners that no marathoner's resume is complete without at least facing the hills and headwinds in Boston.

"I think he can be very content. But there would always be that question mark: How would he do on this course? And could he get it done and win here?" said Des Linden, a two-time Olympian and the 2018 Boston champion. "So it's great that he's coming out to get that answer."

Kipchoge has four victories each in Berlin and London, and one each in Chicago and Tokyo - all flat courses. He has also never run the New York Marathon, but said winning all six major marathons is his goal.

Having never even been to Boston before this week, one of his first missions was to scout out the course, which begins with a quad-crunching descent, slaps runners with the trademark Heartbreak Hill around the 32km mark, and then drops down to sea level again in the Back Bay.

He said he knows it is not a course that lends itself to fast times but would be quite satisfied to win a slower and more tactical race.

"I don't mind about time," he said, "but I will try to win."