Selection Sunday

Happy Selection Sunday!

Green beer and lucky leprechauns aside, today is one of America’s great (unofficial) holidays. It’s the day the 68-team brackets for the N.C.A.A. men’s and women’s basketball tournaments are revealed.

Tonight’s unveiling of the matchups may bring back a feeling you haven’t had since digesting the prompt for that 10th grade U.S. history essay: What in the world do I make of all this?

Did Duke get a favorable draw? What’s the path for my school? Which No. 12 seed looks like a Cinderella? Where the heck is McNeese State? Is Cream Abdul-Jabbar in the field? And how come the Fairfield women’s team is called the Stags?

No matter how much basketball you’ve studied since November — poring over KenPom ratings, streaming games from obscure conferences, reciting the eight-player rotations of the Purdue men and the South Carolina women before you go to bed — there is so much uncertainty when it comes to filling out your bracket.

Picking winners has never been simple — remember, over all these years, there has never been a perfect bracket — but recent changes to the sport have made it more unpredictable than ever. I’ll explain them in today’s newsletter.

New rules

Three years ago, under mounting legislative and judicial pressure, the N.C.A.A. changed two major rules. It allowed athletes to make money from so-called name, image and likeness payments, and it eased restrictions on players transferring from one school to another. Those changes — prompted in part by a Supreme Court ruling that weakened the N.C.A.A.’s authority — have upended the top levels of college sports.