While the first minor league post-season interleague championship series dates to the 1904 Little World Series, commemorative game balls date only back to 1983 (at least, as far as I know), when a unique game ball was used for the first Triple-A World Series.
The last interleague post-season series involving a level lower than Triple-A was the 1967 Dixie Series between the champions of the Double-A Southern and Texas leagues. Since then the only interleague championship play has been at the Triple-A level.
A complete list of all minor league post-season series is just one of the reasons to buy The Collector’s Guide to Minor League Baseballs!
Triple-A World Series, 1983
The first Triple-A World Series (or, the first Triple-A championship under that name; the event had been held sporadically for decades, first known as the Little World Series and later as the Junior World Series, until 1975) was played in 1983, a round-robin tournament between the then-three highest minor leagues (American Association, International League, and Pacific Coast League). This turned out to be a one-time event.
Triple-A Classic
The leagues would not meet again for a post-season series until 1988. The Triple-A Classic was a best-of-seven between the champions of the American Association and the International League; the PCL didn’t participate. Games were scheduled like the Major League World Series, a 2-3-2 format. The American Association won all four of these contests, from 1988-1991.
Triple-A World Series, 1998-2000
Six years passed before the Triple-A World Series was revived. In 1998 MiLB reorganized Triple-A ball, folding American Association teams into the IL and PCL to leave just two leagues. League champions would meet in a best-of-five series to be held at the same site each year, Cashman Field in Las Vegas. This proved to be a sponsorship success but an attendance and TV ratings failure, and it was scrapped after three years. (I’m happy to say my hometown Indianapolis Indians won the title in 2000!)
The Bricktown Showdown
In 2006 the IL and PCL established a single National Championship Game. From 2006-2010 it was again held at a theoretically neutral site, this time Oklahoma City’s AT&T Bricktown Ballpark, and thus was informally known as the The Bricktown Showdown.
Triple-A National Championship Game
A version of the 2012 NCG ball exists with no sponsor on the logo.
From 2011 through 2019 (the 2020 season was cancelled) the game was held in a different city each year, alternating between an AL affiliate and an NL affiliate.
The first season of MLB’s direct management of the minor leagues, 2021, saw no post-season game nor series at the Triple-A level. The Double-A, High-A, and Low-A leagues each held a best-of-five playoff series between their respective two teams with the best record, but there was no interleague play.
Triple-A Triple Championship Weekend
Post-season play returned to the Triple-A level in 2022 with the Triple-A Triple Championship Weekend. Taking place over three days, the two division winners in the International League played one game and the two division winners in the Pacific Coast League played one game to determine each league’s champion. Those two teams then played one final game to decide the Triple-A title.
There was no special game ball.
2023 Revamp
For 2023 the post-season format was changed again.
TRIPLE-A
In each league a first-half winner and a second-half winner will meet for a best-of-three series to be hosted by the first-half winner. The two victors will then meet for one Championship Game in Las Vegas.
Again, there was no special game ball.
DOUBLE-A, HIGH-A, SINGLE-A
The lower leagues will also divide their seasons into halves, with the two half winners meeting in a best-of-three Division Series, followed by a best-of-three Championship Series. The lone exception is the Northwest League which, consisting of only six teams, will play a single, best-of-five Championship Series between the two half-season winners.
Independent Leagues
