LSU’s Ben Simmons is a ludicrously versatile basketball prodigy whose freshman numbers already compare favorably with greats of the past. He’ll probably go first overall in this summer’s NBA draft, and deservedly so. But for all of Simmons’s brilliance, his Tigers aren’t very good — they rank 75th in Ken Pomeroy’s ratings, and at 18-12 they’re a long shot to make the NCAA Tournament.This pairing of an exceptional individual and an unremarkable team is pretty rare. When a team has a prospect as good as Simmons, it doesn’t usually lose before the second weekend of the tourney, much less miss the field entirely. To measure this, I gathered ESPN’s prospect rankings for collegiate players from 2001 through last season, tracking how far their teams went in the postseason during their final NCAA season. Among top-five prospects in that span — and Simmons ranks No. 1 this year — 87 percent were on teams that made the NCAA Tournament, with about half going as far as the Elite Eight before losing. The rest of the No. 1s went far — and I mean really far. Half went to the Final Four, and a third went to the national title game. They didn’t do it alone, though. Shane Battier, Anthony Davis and Greg Oden, for instance, generated almost exactly 25 percent of their teams’ win shares when they blazed a path to the championship game. Simmons has been a bit less productive than that trio on a per-minute basis, but he’s also generated 33 percent of LSU’s win shares this season, with his teammates creating roughly 45 percent fewer wins per game than those of Battier, Davis and Oden. If Simmons had anything close to their supporting casts, LSU probably wouldn’t be fretting about Selection Sunday.Instead, we’ll probably be left with a March Madness that doesn’t feature the nation’s best NBA prospect. That isn’t unprecedented, but it is pretty rare — and, mainly, it’s a bummer because Simmons is such an electrifying all-around talent in a sport that needs all the excitement it can get. The crew of prospects Simmons will join if LSU fails to make the tournament isn’t exactly bad — even Steph Curry ended his Davidson career in the NIT, after all. (Granted, Davidson in the Southern Conference and LSU in the Southeastern Conference are apples and oranges; perhaps a better comp for Simmons is Chris Bosh, who couldn’t elevate Georgia Tech into the tournament out of the ACC in 2002-03.) But the distribution of basketball talent is steep. Top draft picks are, on average, so much better than their peers that a No. 1-ranked prospect should probably be held to a higher standard than the rest of the top five.And, sure enough, in the 15 years before Simmons only one No. 1 prospect was on a team that missed the NCAA Tournament: Nerlens Noel, in 2012-13. The other 92 percent of No. 1s at least got to the round of 64, and even Noel’s case comes with a huge asterisk. Before Noel was lost for the season with a knee injury, his Kentucky team was on the bubble at 17-6, but improving; afterward, the Wildcats closed out the season 4-5 and stamped a nonrefundable ticket to the NIT.