One leg of the biggest annual multi-day sporting event in the country comes to Boston when the third and fourth round games of the East Regional of the 2018 NCAA Division I Men’s Basketball Championship stop at the TD Garden. The third round match-ups (part of the so-called “Sweet 16”) on March 23 consist of two games, the winners of which face off in the “Elite 8” round on March 25 to determine which team moves on to the Final Four in San Antonio. Whether you’re a basketball fanatic or just a casual participant in your office’s bracket pool, this is a rare opportunity to witness “March Madness” first-hand right here in the Hub.