NCAA volleyball: Teams from these conferences are most likely to bust your bracket

The Michigan State Spartans were the only unseeded team to make the regional finals of the 2017 NCAA volleyball tournament, but they were far from the only team to upset a national seed along their way to being the biggest surprise of the tournament.

Since the championship field expanded to 64 teams in 1998, there have been 101 games where an unranked team beat a team with a national seed or a double-digit national seed beat a single-digit national seed. We looked at every one of those games to determine which conference has the teams most likely to rattle off upsets and wreck your bracket.

Unsurprisingly, the Big Ten had the most upsets, with 33, from 1998 through 2017, while the Pac-12 was second with 18. The Big 12 and the West Coast Conference were the only other two conferences with double-digit upsets with 11 and 10, respectively.

It’s worth noting that in 1998 and ‘99, there were four national seeds per region. In 2000, the tournament moved to the current system of ranking teams Nos. 1-16.

RELATED: How low a team can be in RPI and still make the tournament as an at-large

These are some other trends that stuck out when looking at the upsets:

• 56 of the 103 upsets of national seeds in the tournament since 1998 occurred in the second round, with only five happening in the first round.
• 18 of those 56 second-round upsets were unranked teams defeating single-digit national seeds. Minnesota upset No. 4 Southern California in the Central Regional and Arizona upset No. 4 Texas in the Pacific Regional in 1999, as well.
• BYU had the most upsets as an unranked team with six. Michigan and Michigan State were close behind with five.
• Michigan tied with BYU for the most upsets of any team since the field expanded to 64 teams with six.

Below is the full list of upsets of national seeds from 1998 through 2017 sorted by conference. In a couple cases — like BYU being in the Mountain West and then the WCC — the conference the team was in at the time of the upset is reflected in the chart. For teams like Stanford or Oregon that were in the Pac-10 before it was renamed to Pac-12, we listed the conference as Pac-12 since those teams didn’t change conferences.

MORE: 92 volleyball teams that haven't made NCAAs | 5 takeaways from the new AVCA rankings