King of the Diamond
What if baseball determined its champions in the same way that boxing and wrestling do? That is, the last team standing becomes the new champ.
You may have never asked yourself that question, but I have. So I’ve decided to run a single-season experiment last year to finally answer it. (You can see those results here.) I enjoyed it so much, I’m doing it again this year.
The rules are simple: The last team to lose a game in each league during the 2025 season becomes the respective league champion (and the last between those two becomes the overall champ). After that, whichever team defeats the reigning title holder takes the theoretical belt.
Rules clarifications
Okay, apparently the rules aren’t that simple after all. Some more details:
- Only regular season games are included as part of this experiment. Exhibition and postseason games are not included.
- The AL/NL championships are not at stake in interleague games.
- Title reigns are measured in days, not games. A reigning champion still accrues championship streak days during interleague series, postponed or suspended games, and off days, as long as there’s at least one other MLB game on the schedule that day.
- The league-wide off days around the All-Star Game do not count. (July 14–17)
- The days in the awkward gap between the Dodgers-Cubs opening series in Tokyo and the rest of the regular season (March 20–26) do not count, but they really wouldn’t anyway—the first champion cannot be declared until each team has played at least one game.
- Title days are accrued at the end of the scheduled day. In the case of a split doubleheader, the winner of the first game does not earn a championship day, but the team winning the second game does. Both teams earn one championship for their overall count.
- The final results of suspended and makeup games are counted on the day that they are completed, not the day that they were originally scheduled.
- If two teams share a title, then each team accrues a full day of streak time. This is only possible in the rare case of a declared tie involving the current champion at the end of the season. Normally, tied games are suspended and concluded at a later date and are accounted for using the rules outlined above.
Current champions
(Through all games played as of March 29, 2025)
MLB
AL
NL
How they got here
MLB Championship
- On March 30, the Phillies lost, leaving 4 teams (Cardinals, Dodgers, Padres, and Yankees) undefeated.
- On March 29, the Giants, Guardians, Rays, and White Sox lost, leaving 5 teams (Cardinals, Dodgers, Padres, Phillies, and Yankees) undefeated.
- On March 28, the Astros, Mariners, Marlins, Orioles, Red Sox, and Rockies lost, leaving 9 teams undefeated.
- On March 27, the Angels, Athletics, Blue Jays, Braves, Brewers, Diamondbacks, Mets, Nationals, Pirates, Rangers, Reds, Royals, Tigers, and Twins lost, leaving 15 teams undefeated.
- On March 18, the Cubs lost to the Dodgers, leaving 29 teams undefeated.
American League Championship
- On March 29, the Guardians, Rays, and White Sox lost, leaving the Yankees as the last remaining undefeated team and inaugural champion in the AL.
- On March 28, the Astros, Mariners, Orioles, and Red Sox lost, leaving 4 teams (Guardians, Rays, White Sox, and Yankees) undefeated in AL play.
- On March 27, the Angels, Athletics, Blue Jays, Rangers, Royals, Tigers, and Twins lost, leaving 8 teams (Astros, Guardians, Mariners, Orioles, Rays, Red Sox, White Sox, and Yankees) undefeated in AL play.
National League Championship
- On March 30, the Phillies lost, leaving 3 teams (Cardinals, Dodgers, and Padres) undefeated in NL play.
- On March 29, the Giants lost, leaving 4 teams (Cardinals, Dodgers, Padres, and Phillies) undefeated in NL play.
- On March 28, the Marlins and Rockies lost, leaving 5 teams (Cardinals, Dodgers, Giants, Padres, and Phillies) undefeated in NL play.
- On March 27, the Braves, Brewers, Diamondbacks, Mets, Nationals, Pirates, and Reds lost, leaving 7 teams (Cardinals, Dodgers, Giants, Marlins, Padres, Phillies, and Rockies) undefeated in NL play.
- On March 18, the Cubs lost to the Dodgers, leaving 14 teams undefeated.
Records
| Most times as champ (MLB) | – |
| Most days as champ (MLB) | – |
| Longest streak (MLB) | – |
| Most times as champ (AL) | New York Yankees (1) |
| Most days as champ (AL) | New York Yankees (2) |
| Longest streak (AL) | New York Yankees (2) |
| Most times as champ (NL) | – |
| Most days as champ (NL) | – |
| Longest streak (NL) | – |
Number of days as champion
MLB
| ARI | – |
| ATL | – |
| BAL | – |
| BOS | – |
| CHC | – |
| CHW | – |
| CIN | – |
| CLE | – |
| COL | – |
| DET | – |
| HOU | – |
| KC | – |
| LAA | – |
| LAD | – |
| MIA | – |
| MIL | – |
| MIN | – |
| NYM | – |
| NYY | – |
| PHI | – |
| PIT | – |
| SAC | – |
| SD | – |
| SEA | – |
| SF | – |
| STL | – |
| TB | – |
| TEX | – |
| TOR | – |
| WAS | – |
AL
| NYY | 2 |
| BAL | – |
| BOS | – |
| CHW | – |
| CLE | – |
| DET | – |
| HOU | – |
| KC | – |
| LAA | – |
| MIN | – |
| SAC | – |
| SEA | – |
| TB | – |
| TEX | – |
| TOR | – |
NL
| ARI | – |
| ATL | – |
| CHC | – |
| CIN | – |
| COL | – |
| LAD | – |
| MIA | – |
| MIL | – |
| NYM | – |
| PHI | – |
| PIT | – |
| SD | – |
| SF | – |
| STL | – |
| WAS | – |
Number of times as champion
MLB
| ARI | – |
| ATL | – |
| BAL | – |
| BOS | – |
| CHC | – |
| CHW | – |
| CIN | – |
| CLE | – |
| COL | – |
| DET | – |
| HOU | – |
| KC | – |
| LAA | – |
| LAD | – |
| MIA | – |
| MIL | – |
| MIN | – |
| NYM | – |
| NYY | – |
| PHI | – |
| PIT | – |
| SAC | – |
| SD | – |
| SEA | – |
| SF | – |
| STL | – |
| TB | – |
| TEX | – |
| TOR | – |
| WAS | – |
AL
| NYY | 1 |
| BAL | – |
| BOS | – |
| CHW | – |
| CLE | – |
| DET | – |
| HOU | – |
| KC | – |
| LAA | – |
| MIN | – |
| SAC | – |
| SEA | – |
| TB | – |
| TEX | – |
| TOR | – |
NL
| ARI | – |
| ATL | – |
| CHC | – |
| CIN | – |
| COL | – |
| LAD | – |
| MIA | – |
| MIL | – |
| NYM | – |
| PHI | – |
| PIT | – |
| SD | – |
| SF | – |
| STL | – |
| WAS | – |
Team logos courtesy of SportsLogos.net