The N.C.A.A. announced on Friday that it would welcome fans — tens of thousands of them — to Indianapolis and San Antonio, where the entire men’s and women’s basketball tournaments are to be held this season, in a move that will generate millions in ticket revenue but risk further spread of the coronavirus to and from far-flung regions of the country.
The 68-team men’s tournament, which begins on March 18, will be played in Indianapolis before crowds of up to 25 percent capacity at sites ranging from the quaint 9,100-seat Hinkle Fieldhouse, where the movie “Hoosiers” was filmed, to the cavernous Lucas Oil Fieldhouse, which in a normal year could hold up to 70,000 fans for the regional finals and the Final Four.