Over the past two years, wheelchair racer Tatyana McFadden has been unbeatable. Now she's going for the "Tatyana Slam" in marathons ... times two

If Tatyana McFadden wins the New York Marathon this coming weekend, it will be her eighth straight victory in the world's most prestigious races: Boston, London, Chicago and New York. Last year, she swept all four. Now she's on the verge of doing it again. My story for ESPN.com: http://espn.go.com/sports/endurance/story/_/id/11772889/endurance-sports-tatyana-mcfadden-looking-another-marathon-grand-slam