Here's how to pick March Madness men's upsets, according to the data

Dust off your crystal ball because it's time to get ready to make this year's March Madness selections.

Whatever your sweet spot is for predicting upsets in the NCAA tournament, there is one important question that applies to every fan: How many upsets should I pick?

We examined the last 38 NCAA tournaments since the field expanded to 64 teams in 1985 and crunched the numbers for each round. Now we're here to encourage you to make as many upset picks as possible without going overboard.

First, let's set some ground rules. We defined an "upset" as when the winning team in an NCAA tournament game was seeded at least five seed lines worse than the losing team. There are too many common matchups where the difference in seeding is only one seed line (e.g. the 8/9 game in the first round, the common 4/5 game in the second round, and a 1/2 matchup in the Elite Eight), so it seems to take away from the spirit of an "upset" to say that a No. 9 seed beating a No. 8 seed is an upset.

Using this definition of an upset, there have been at least 10 upsets in 15 of the past 38 seasons. The annual average is roughly 8.5 upsets. There have been as few as three upsets (2007) and as many as 14 (2021 and 2022) but the sweet spot is obviously somewhere in between. Upsets have become more frequent lately as well: There have been at least 10 upsets every year since 2021 and at least 10 in nine of the past 12 years. There were exactly 10 in the 2023 NCAA tournament.

If you're a calculated risk taker, try for 11 upsets. That's happened five times (1986, 2002, 2006, 2011 and 2013). If you want to play it somewhat safe — i.e. "How many upset picks is too few?" — then five to seven is a good number to try to hit. There have only been 12 NCAA tournaments in the last 38 years in which there were fewer than seven upsets in a single NCAA tournament, and only once since 2010. The 2007 tournament is the only year in which there was fewer than five upsets.

Here's the full breakdown.

So, to answer the first question posed earlier, 15 upsets is probably too many to pick and five is probably too few.

Now, onto an equally important question: Where should those upset picks be made? Looking at the averages listed above, your number of upset picks should roughly be half as many as there were in the previous round, given both the number of games per round and the quality of teams that advance each round.

Here's a breakdown for the first round of each upset based on seed lines, the number of times such an upset has occurred since 1985 and the percentage of the time such an upset has happened.

The individual matchups for upsets, in terms of seeding, become less common after the first round, based on the results of the first round games. But in keeping with the rule that an upset is defined by a seed ranked at least five spots worse, we combined some of the seed lines within individual four-team pods (e.g. a No. 7/No. 10 seed upsetting a No. 2 seed or a No. 8/No. 9 seed upsetting a No. 1 seed), it'll provide a clearer picture for how many upsets you should pick in your bracket.

Related: 7 signs you're picking too many upsets

Teams seeded No. 7 or No. 10 have upset a No. 2 seed 46 times in the past 38 tournaments (roughly 1.2 per year), so history tells us you should probably pick at least one No. 2 seed to lose in the second round. On average, a No. 1 seed has lost about once every other year in the second round.

Here's the full second round breakdown: