Edit: We've updated this post here to add the 2015 Cubs. They did not come back, either.
The Baltimore Orioles are down three games to none in the American League Championship Series. Rest in peace, 2014 Baltimore Orioles. It was a good run. We will bury you in the finest shoebox available.
Except, hold on, wait, wait, wait. Are you telling me the Orioles are completely incapable of winning a four-game series against the Royals? The 2005 Orioles won four games straight once, and they won five games all season. The 2014 Orioles had a four-game winning streak or better on four separate occasions. Sure, none of them were against a team as good and confident as the Royals, but the streaks still happen. The Orioles can win four games in a row.
The Orioles can win four games in a row.
Edit: They did not win four games in a row
When it comes to best-of-seven playoff series, though, there's something afoot. Something weird.
Let's assume that in every best-of-seven situation in which a team goes up three games to none, the team that's up is a quantifiably better team. This probably isn't true in all (most?) cases, but let's assume that in these series, the favorite should win 55 percent of the game, and the underdog should win 45 percent. As in, if the Orioles and Royals played a 162-game season, the Orioles would finish 73-89, and the Royals would finish 89-73. That seems ... extreme, but we're erring on the side of caution.
With this probability, you would expect a team down 0-3 to win four percent of the time (.45*.45*.45*.45 = .04100625). There have been 33 different best-of-seven series in MLB postseason history that have started 0-3. Only one team came back to win, the 2004 Boston Red Sox in the ALCS. That's three percent of the total scenarios -- right in line with what we should expect. If you give each team a 50/50 shot at winning any given game, which is probably closer to reality once you get to the playoffs, at least in the modern era, it's closer to a six-percent chance. So just having one comeback seems low, but not unusually so.
That's not the freaky part, though. That's not why the Orioles are in such a deep hole. Here are all of the best-of-seven series that started with a 3-0 lead in MLB postseason history, followed by the eventual finish of the series:
League Championship Series
1988 - Oakland Athletics over Boston Red Sox (4-0)
1990 - Oakland Athletics over Boston Red Sox (4-0)
1995 - Atlanta Braves over Cincinnati Reds (4-0)
1998 - San Diego Padres over Atlanta Braves (4-2)
1999 - Atlanta Braves over New York Mets (4-2)
2004 - Boston Red Sox (down 0-3) over New York Yankees (4-3)
2006 - Detroit Tigers over Oakland Athletics (4-0)
2007 - Colorado Rockies over Arizona Diamondbacks (4-0)
2012 - Detroit Tigers over New York Yankees (4-0)
2014 - Kansas City Royals over Baltimore Orioles (4-0)
1907 - Chicago Cubs over Detroit Tigers (4-0-1)
1910 - Philadelphia Athletics over Chicago Cubs (4-1)
1914 - Boston Braves over Philadelphia Athletics (4-0)
1922 - New York Giants over New York Yankees (4-0-1)
1927 - New York Yankees over Pittsburgh Pirates (4-0)
1928 - New York Yankees over St. Louis Cardinals (4-0)
1932 - New York Yankees over Chicago Cubs (4-0)
1937 - New York Yankees over New York Giants (4-1)
1938 - New York Yankees over Chicago Cubs (4-0)
1939 - New York Yankees over Cincinnati Reds (4-0)
1950 - New York Yankees over Philadelphia Phillies (4-0)
1954 - New York Giants over Cleveland Indians (4-0)
1963 - Los Angeles Dodgers over New York Yankees (4-0)
1966 - Baltimore Orioles over Los Angeles Dodgers (4-0)
1976 - Cincinnati Reds over New York Yankees (4-0)
1989 - Oakland Athletics over San Francisco Giants (4-0)
1990 - Cincinnati Reds over Oakland Athletics (4-0)
1998 - New York Yankees over San Diego Padres (4-0)
1999 - New York Yankees over Atlanta Braves (4-0)
2004 - Boston Red Sox over St. Louis Cardinals (4-0)
2005 - Chicago White Sox over Houston Astros (4-0)
2007 - Boston Red Sox over Colorado Rockies (4-0)
2012 - San Francisco Giants over Detroit Tigers (4-0)
First thought: Cut it out, Yankees. Second thought: Wait a second ...
The story isn't just that one team came back. It's hard to beat a good team four times in a row. It's hard to beat a bad team four times in a row. That's the nature of baseball, and it's what makes the postseason more unpredictable than the NFL or NBA. The Red Sox are the only team so far. Eventually, there will probably be another one, but it'll take some time.
The real story is the distribution:
Series that made it to a fifth game
Five of 33
Series that made it to a sixth game
Three of 33
Series that made it to a seventh game
One of 33
That's kind of bizarre. If we use the flawed 45-percent model, we still should have had about 14 series that made it to a fifth game. About six or seven of them should have made it to a sixth game. About three of them should have made it to a seventh game. Instead, 28 series out of 33 ended in a four-game sweep, as if the other team just ... let go.
That can't be what happened, though, right? Alternate explanations:
I'm an English major, and I'm absolutely expecting someone to come in here and post a comment about binomial distribution and r-squareds and rhombuses. That's fine. I'm not claiming to have done a mathematical proof. BRING YOUR WORST, ABACUS-TWIDDLERS.
It does seem like a small enough sample, though, that a pair of comebacks in the next few years would make the numbers look a lot more normal. Thirty-two series just aren't a lot.
Quality of teams
If the 1927 Yankees played the 1927 Pirates for 162 games, they still might win 95 games. Not just that team, either. The Yankees were clearly better than their opponents for a couple decades, enough to futz with the 45-percent model.
They're hard to quantify, so it's easier to ignore them, but they're also easy to blame. Doesn't a little pep get taken out of the step after three straight losses and historically insurmountable odds? What about the first lead that the other team takes in any of the games that follow? Don't the shoulders slump just that much more? What if it's not the entire team, but one mopey SOB who was going to wash out of the league in a year or two because he's too danged mopey?
That seems unlikely, considering the winnowing process the minor leagues should have on players without a lot of mental fortitude, so I'll eliminate it.
Give me the first one. We're probably going to hit a freaky run of 0-3 comebacks over a decade, and the overall numbers will stabilize. But the Orioles are facing steep odds. You knew that already, but you might not have known just how steep the odds were for them to reach a Game 5 at all.