Nine. Of all the numbers that describe the disastrous September of the Boston Red Sox, most will remember nine. That's how many games the Tampa Bay Rays trailed Boston in the AL wild-card race going into Sept. 4.
Boston's subsequent September collapse goes down as the worst in major league history, edging a simultaneous faltering by the Atlanta Braves, who held an 8½-game lead over the St. Louis Cardinals for the NL wild card that they couldn't hold.
While nine might live on, there are plenty of other numbers that put Boston's collapse into context.
According to CoolStandings.com, the Red Sox had a 99.6 percent chance at making the postseason when they woke up on Sept. 4. Based on their formula, there have only been two teams with a better percent chance at the postseason on that date who came up short: 1951 Dodgers and 1995 Angels.
On Wednesday night at about 10:22, Boston's odds of playing another day were even higher. At that point, the Rays trailed the New York Yankees 7-0 going into the bottom of the eighth inning. That gave them a win probability of 0.58 percent. That doesn't even take into account the fact that the Yankees had won 925 straight games with a lead of seven or more runs in the eighth inning or later, according to Elias. (Last loss? 1953!)
At that same time, the Red Sox were still stuck in a rain delay. But up 3-2, they had a 60.0 percent chance of winning the game.
Putting those two pieces together, at 10:22, the Red Sox had a 99.8 percent chance of at least playing in a one-game tiebreaker on Thursday, according to ESPN analytics specialist Alok Pattani. In other words, at that point in time, there was a 1-in-431 chance that the Red Sox's season would end that night.
The Red Sox didn't just have a bad month in comparison to the rest of season. Boston's September woes were historically bad by any measure. In fact, it was the Red Sox's worst full month of baseball in 47 years. At 7-20, their .259 winning percentage was the lowest in a month of at least 15 games by a Red Sox team since August 1964. They finished that month 7-22 (.241) and averaged just 2.9 runs per game.
But rather than winning 90 games, as Boston did in 2011, that 1964 team lost 90. Just how long ago was it? Johnny Pesky managed that team. At 44, he was eight years younger than Terry Francona is now. Pesky is now 92.
The Red Sox matched a franchise-record with 20 losses in the month of September. That also happened in 1952, a month in which Ted Williams was limited to six games because of military service.
The Elias Sports Bureau dug up some even more amazing historical context. The 2011 team tied a major league record for most losses from Sept. 1 to the end of the season by a team that entered the month in first place. In 1914, the New York Giants started the month in first and closed out the season with a 21-20 record. So it took them 14 more games than Boston to reach 20 losses.
The Red Sox went through the entire month of September without winning back-to-back games. In fact, you have to go back to a doubleheader sweep of Oakland on Aug. 27 to find the last time Boston posted consecutive wins. According to Elias, that span of 30 games without back-to-back wins was the longest for the franchise since 1979.
Quite simply, the Red Sox's starting rotation had its worst month -- ever. The 7.08 ERA is the highest in franchise history in a month with at least 20 games. The previous mark occurred in August 1997, when the Red Sox had assembled a patchwork rotation in between the Roger Clemens and Pedro Martinez eras.
The seven starters used by the Red Sox combined to go 4-13 and managed only five quality starts. Things were particularly bleak at Fenway: 3-7, 7.21 ERA.
Just how unreliable were the starters? Alfredo Aceves didn't start a game all month, and still finished second on the team in innings pitched in September.
The bullpen had a comparatively acceptable 4.45 ERA during the month. Overall, the pitching staff's 5.84 ERA was the highest ever for a Red Sox team in September. It was also Boston's highest in any month since June 1994 (5.88).
Daniel Bard had the most unfortunate month on a staff of dismal performances. He finished September 0-4 with a 10.64 ERA, issuing more walks (nine) than he had in the previous three months combined (eight). Based on win probability added (WPA), the player most responsible for Boston's collapse was Bard, followed by Jarrod Saltalamacchia.
He's the first Red Sox pitcher to lose four games in relief in a month since Derek Lowe's disastrous April 2001. It's been much longer since a Red Sox reliever lost four games in September: Ellis Kinder in 1955. It was the last hurrah with the Sox for Kinder, who once finished in the top five of the MVP voting for Boston. The Cardinals plucked him off waivers in the offseason.
If Bard had the ugliest September on the staff, Andrew Miller wasn't far behind. Consider that Kyle Weiland, who essentially took Miller's spot in the rotation, posted an 8.53 ERA in four starts. As bad as that was, it was still an improvement over Miller.
Right-handed batters posted a .548 on-base percentage against Miller, who only threw 50 percent strikes against them.
His 11.70 ERA is the highest for a Red Sox pitcher in September (minimum 10 innings) in the post-World War II era. That distinction previously went to Jack Lamabe's 10.80 ERA in 1964. Bard's 10.64 ERA this month winds up third on the list. That both Bard and Miller pitched double-digit innings despite their struggles is a clear indictment of the lack of pitching depth.
It's easy to blame a rotation that posted a 7.08 ERA or a bullpen that accounted for seven losses. After all, the offense scored more runs (146) than it did in two more games in August (143), while hitting .280. However, those numbers are skewed from a few offensive outbursts. In their seven wins, the Red Sox scored 81 runs (11.6 per game). In the 20 losses? Just 65 runs (3.3 per game). In eight of those losses, the offense managed two runs or fewer.
Pitching and injuries are the easiest scapegoats for Boston's disastrous month. However, the Red Sox also did themselves no favors with their defense, committing an MLB-high 26 errors. Compare that to just 66 errors in their first 135 games. On top of its historically high ERA, the team also allowed 14 unearned runs in September, tied for the fourth most in the majors.
Even amidst the disheartening April start and the torturous September, the Red Sox could count on maintaining a ninth-inning lead. According to Elias, Boston was 89-0 this season in games in which it led in the ninth inning or later. That is, until Wednesday.
Jeremy Lundblad is a senior researcher with ESPN Stats & Information. He provides statistical analysis for ESPNBoston.com.