It's the first round where you have two teams that are on a roll.
That 9+ seed that got an upset in the first round, EVERYONE is watching their game, and if they win, wow, everyone loves them. And, if they have a nun?
It's probably the last round where there will be multiple surprising upsets, or just little guys making a big team sweat.
It's Sat and Sunday, alll day. You can just turn on the tv. Any time, and basketball. And, you have games to choose from. Better chances to have close games. And, it's Sat and Sunday. You can have a few pops. You can even go to a sports bar. And, spend the better part of the day.
For me, the first weekend is what makes March mad.
Here's what AI says about upsets per round:
🥇 By percentage of games (upset rate)
👉 Sweet Sixteen (regional semifinals)
~21% upset rate (since ~2003)
Slightly higher than:
First Round: ~20.0%
Second Round: ~19.9%
Why this happens
By this point, you’ve eliminated most weak teams
Matchups become tighter (often 2–3 vs 6–7 type gaps)
The definition of “upset” (≥5 seed difference) still triggers frequently
👉 So on a per-game basis, the Sweet 16 is actually the most “dangerous” round.
🥇 By total number of upsets (volume)
👉 First Round (Round of 64) — by a wide margin
~6+ upsets per year on average
Record: 8 first-round upsets (e.g., 2016)
Why it dominates
There are 32 games (most of any round)
Huge seed gaps (e.g., 5 vs 12, 4 vs 13, etc.)
Classic “Cinderella” zone
👉 Even though the percentage isn’t the highest, the sheer number of games makes it the upset leader.