History will be made in Nashville Tuesday night, when the 39-0 Connecticut Huskies face the 37-0 Notre Dame Fighting Irish for the NCAA Women’s Division I Basketball Championship. It’s the first time a pair of undefeated teams has ever played in the women’s championship game, and only the second time two unbeaten teams have met in the women’s NCAA Tournament at all. The meeting of two such teams — with so much at stake — is a remarkable circumstance, and it had us wondering how it stacks up against other undefeated showdowns.

In men’s college basketball, two unblemished teams have never clashed in the championship game. Probably the closest it came to happening was in 1976, when both Indiana and Rutgers entered the NCAA Tournament undefeated and both squads advanced to the Final Four. Indiana beat UCLA in one national semifinal, but Michigan upset Rutgers in the other semifinal to prevent a meeting of the unbeatens.

The men’s bracket has never seen two undefeated teams enter simultaneously since that historic 1976 NCAA Tournament. Since 1979-80, the best combined record of any undefeated teams in a major men’s game was 33-0 (a pale comparison to UConn-Notre Dame’s combined 76-0 record), achieved when 17-0 North Carolina faced 16-0 Duke on Jan. 18, 1986, well before the tournament began.

Here are the teams that combined for an undefeated record of 20-0 or better in a men’s college basketball matchup since 1979-80:

And that’s just college basketball, where there are 350 Division I teams. In a league like the NBA, which has 30 squads, teams are hard-pressed to avoid each other on the schedule long enough to push their combined records anywhere near 76-0. (Pro sports’ greater parity doesn’t help either.) The winningest matchup of undefeated records in NBA history is just 11-0. That’s when the 5-0 Seattle SuperSonics hosted the 6-0 Utah Jazz on Feb. 16, 1999. The Sonics ran away with it, beating the Jazz 71-56.

The following NBA games saw the two teams combine for an undefeated record of 8-0 or better:

Coincidentally, a combined record of 11-0 is also the high-water mark for Major League Baseball during the AL-NL era. On April 13, 1992, the 6-0 Toronto Blue Jays hosted the 5-0 New York Yankees. In a testament to baseball’s competitive balance (at least, relative to a deterministic sport like basketball) and its series-based schedule structure, most MLB matchups don’t even make it that far:

Professional football has never seen a championship matchup featuring two undefeated teams, either. If we include the All-America Football Conference, the record for most combined wins without a loss in a professional pigskin matchup is 19, set when the 9-0 Cleveland Browns met the 10-0 San Francisco 49ers on Nov. 14, 1948. But if you’re a stickler for NFL games only, the record is 17.5 combined wins (counting a tie as half a win), set by the New York Giants (8-0-1) and Green Bay Packers (9-0) on Nov. 24, 1929.

Here are the games deepest into a pro football season featuring two unbeaten teams:

College football provides the most apt comparison to Tuesday’s battle, since intra-conference play often keeps the best teams in the country separated until the championship. Historically, undefeated teams have met up 37 times in bowl games — 18 times with national championship implications during the Associated Press poll era :

Even so, because college football’s schedules are so much shorter than college basketball’s, the most combined wins two undefeated teams have ever had in a bowl game is 26, a far cry from Tuesday’s 76.

So as Connecticut and Notre Dame get set to take the floor Tuesday night, appreciate the rarity of their 76-0 combined record. It’s a number that has never been approached before, and is unlikely to occur again — regardless of the sport or the gender of the athletes.

Editor’s note: A table in this article has been updated to include a game from the 2013-2014 men’s college basketball season, which was originally not part of the data set.