Yeah, I had no idea either. The Wade Blogs has uncovered the evidence, and it couldn't be a better story.

Kurt Vonnegut worked briefly at SI until being told to write a story about a race horse that had jumped the rail and terrorized the infield at a local track. Vonnegut stared at his desk for what seemed like hours before finally departing the building without a word. Inside his deserted typewriter was this: "The horse jumped over the fucking fence."

"When the magazine was only a glint in the eyes of Luce Publications, they hired a bunch of sports writers from yokel venues who, it turned out, couldn’t write. So then they hired a bunch of writers who didn’t care or know squat about sports. I was part of that second batch, having gone broke as only the daddy of six kids on Cape Cod can hit the big casino. So I roamed far from my immediate responsibilities at the Cornell Club, then at the Hotel Barclay, where everybody else was an unmarried Cornellian insurance salesman. At Time-Life, we got out an issue of S.I. every week, never knowing when the first real issue would be published. And I quit before that happened, exactly in the manner described."- KV