We pulled every first-round game from the 2022–2025 NCAA tournaments—128 games—and ran the numbers on spreads, totals, and straight-up results for every seed matchup. Some of it confirms what you already suspected. Some of it will change how you bet the opening round. Here's what you should lean towards:

Bet This

The Under, Everywhere

This is the single strongest signal in the data. First-round games went under 70% of the time, and that's held consistent over the past four years. Teams from different conferences have never played each other. Mid-majors grind the pace down. It's win-or-go-home so defense cranks up. The under hit hardest in two matchups:

If you do nothing else with this data, just bet the under in every 5-vs-12 and 7-vs-10 game. That's the sharpest edge in the first round.

Lay the Points With 2 and 3 Seeds

Favorites covered 67% of the time in 2-vs-15 games and 70% in 3-vs-14 games. Those are the two best ATS rates in the entire bracket. The lines are usually in the mid-to-high teens, and the higher seeds have been blowing right through them.

Bet On 12 and 11 Seed Upsets If There's Value

The 5-vs-12 game flipped 38% of the time—6 upsets in 16 games. In 2024, two 12-seeds won (Grand Canyon and James Madison). In 2025, Colorado State and McNeese both pulled it off. This isn't a long shot. It's a third of the time.

6-seeds went 8-8 straight up against 11-seeds. Dead even. A literal coin flip over four years. In 2022 alone, three 11-seeds won. In 2024, another three.

This is where it gets tricky, though. The odds aren't always favorable to hammer all of them with a positive expected return, so be careful.

16 Seeds Covering The Spread

1-seeds went 15-1 straight up. You know that. But favorites only covered 44% of the time in 1-vs-16 games. The lines are massive—usually 25 to 33 points—and even a 20-point win doesn't get there.

If you're betting this game, take the 16-seed and the points. They lose, but they cover.

Go get 'em. As always, please bet responsibly.