Is there something to be said for September momentum?

Andre K, having discussed the meaning of life, ascends the Stairways of Heaven, and rides a unicorn into a romper room of ecstasy while yearning for September success.

Much is always said about teams finishing strong in the regular season because people believe the momentum of a superb finish generally carries on in October.

So is this belief true, or a media fabrication?

Let’s look at the numbers over the last six years:

The biggest takeaway is that over the last six years, five World Series champions have had September winning percentages greater than 0.640. The only champion not to have a winning percentage that high were the 2007 Red Sox, who won 59.3% of their games that September, which is still remarkable.

In short, teams that won the World Series have, in fact, played well in September.

That being said, just because a team finishes strong in September, it doesn’t necessarily mean they’re automatically winning the Series. After all, only one can team win the whole thing. There have been five playoff teams over the last six years who finished with a winning percentage above .700 in September and although four of them made it to their respective league championship series, only one of those teams (2011 Rangers) marched on to the World Series.

One argument against this notion is that there are an extremely limited amount of teams that can make it to the championship round. Even if everyone finished above .700 during September in a given year only two teams can eventually make it to the World Series. This is why we can’t really make much of the low correlation coefficient of 0.35.

On the flip side of the argument – of the 11 teams who finished .500 or worse in September, only two of them reached the LCS. This means that there is likely something to be said for momentum and that strong September finishes can matter.

In short, if you finish strong in September, there’s a good chance that success is going to transfer to October. It’s still better than finishing poorly, though, because the lack of momentum heading into October does seem to hurt those teams.

So what’s in store for 2013 and especially the Red Sox?

Here are the September records for all contending teams:

There’s still about half a month left, but the Red Sox are in good shape so far. You want a team to be confident and dominant heading into the games that really matter. The Sox, Athletics, and Cardinals have to be feeling good about themselves.

Meanwhile, the Rangers, Braves, and Tigers need to right the ship. There’s still plenty of time to do it, but the numbers show that over the last six years, if a team is not .500 in September, they’re not going to hang around much in October.

Categories: 2013 MLB Playoffs Boston Red Sox

About Andre Khatchaturian

View all posts by Andre Khatchaturian
Born in the sunbaked valleys of Southern California, Andre Khatchaturian grew up idolizing Mo Vaughn and as a result, became one of the members of Red Sox Nation West. Andre would later graduate from the University of Southern California with a degree in Mathematical Economics. Wanting to pursue his passions, Andre became involved in sports analytics and has immersed himself in independent quantitative sports research since graduation. This led to his hiring at ESPN in the Stats & Information Group at Bristol, CT where he will be working part-time this year as he works on his Masters degree in Broadcast Journalism from Boston University. He was a proud attendee of Game 5 of the 2008 ALCS and wonders why this game has slowly become one of the forgotten gems in Red Sox history. Follow him on Twitter @AndreKhatch.

3 Responses to “Is there something to be said for September momentum?” Subscribe

  1. New Lyndsay September 14, 2013 at 6:31 PM #

    Like I said on another post, it is a really weird feeling to be in a place as a fan where they’re not trying to get into the playoffs by the skin of their teeth. They did that consistently 2005 onwards and ended up out of it by the first or second round.  I mean, 2004 they were also right on the edge too obviously, but it actually kind of feels nice to not be worried about this team for once. When they were dominating in 2011 pre-September, it felt like flying high on a rollercoaster, but at the same time you were afraid they were going to fly right off of it (as they did). This year doesn’t have the same feeling as previous. I think I started to have this feeling of no worries with the last series with Detroit, when they absolutely killed them, and that was supposed to be one of their toughest series this year. Dare I say it and jinx it, I feel more confident in this team than I have in any team in years – more than 2007 team even, which felt like a very nerve-wracking September.

  2. TroyPatterson September 15, 2013 at 1:04 AM #

    I don’t know how much this is telling us.  A team might have something like 25 to 28 games in the month of September and the difference between a .600 and .640 winning percentage is a single win.  If a team goes 15-10 they have a .600 win percentage and if they are a division leader that might be what they have done all season and “not a hot streak”.  Yet if they go 16-9 suddenly it’s .640 and their are “hot” or have momentum.
    Even the Red Sox only have two more wins than the expected 8 they would have based on their season win percentage this far.

  3. beaneater September 17, 2013 at 5:06 AM #

    TroyPatterson You’re right about the “good September” side of the equation. The difference between .600 and .640 over one month is negligible — both are setting themselves up well for reasonable post-season success. My takeaway is that avoiding a bad September is more crucial than ensuring a wonderful one. Or to put it another way, a great September doesn’t guarantee anything but a lousy September is a bad omen. And the Sox have certainly avoided a lousy September so far.
    Man, this is a fun ride!