A City of Madness, Bypassed by the N.C.A.A.

LAS VEGAS — In three arenas strung along a three-mile stretch of Tropicana Avenue, 19 postseason men’s college basketball games were played on Wednesday and Thursday. The games attracted tens of thousands of fans, with many more watching on television. They were played under rules set by the N.C.A.A., college basketball’s governing body.

With four conference tournaments held in Las Vegas this week (one ended Tuesday; the others end Saturday), there is no spectacle like it in on the college basketball landscape — a neon-lit kaleidoscope featuring dozens of mascots, bands, cheerleaders and fan bases, hoping to cheer their teams to the N.C.A.A. tournament, which starts next week.

One major college basketball participant with no chance of advancing to the national tournament: Las Vegas itself.

This week, it is the mecca of college basketball. Next week, it will be a mere mirage in the desert, suddenly stripped of its ability to host any games in an effort “to ensure the integrity of the game,” according to the N.C.A.A.