August Birthdays and Outliers

by Erik Hahmann on Jan 2, 2009 2:29 PM EST Comment 13 comments

Last week I wrote about Malcolm Gladwell’s book “Outliers”, specifically about the age cut off date for youth hockey leagues in Canada and youth baseball leagues in America and how that ties to Major League Baseball, and the Rays.

Just to give a brief recap, the book showed that if you wanted your child to have the best shot at being a very good hockey player the optimal month of birth was January because the age cut-off date for youth hockey leagues is Jan. 1st. The same thing applies for baseball. The age cut-off date for youth baseball leagues in America is July 31st, and not surprisingly there are more players born in August than any other month. Last season the Rays had seven players on their 40 man roster born in August. They also happened to be one of the best teams in baseball. That got me to thinking; does having more August born players have a direct correlation to team success?

I looked at every team from the 2008 season, and then every playoff from the last five years to see if there was any correlation.

First, the 2008 American League. What I found in the AL was pretty interesting. The three division winners (Rays(7), White Sox(8), Angels(6) finished second, first, and third in most August born players. The Wild Card winning Red Sox came in tied for fifth. Even the AL CY Young and MVP Winners were born in August. While all of that seems to support the question I raised above, I’m afraid it may be a statistical anomaly, an outlier, if you will. Looking at the 2008 National League season doesn’t give us anywhere close to the same results.

The Dodgers finished first in the league with six August born players. That seems to be a good thing, seeing as how they won their division. But five teams (Phillies, Brewers, Cardinals, Pirates, D-Backs) finished tied for second with four players apiece. The Phillies finished first in the East in both the standings and August born players. The Brewers, however, finished a distant second to the Cubs (who had three August players) and tied with the Cardinals and lowly Pirates. In the NL it doesn’t appear that having many August born players made a difference.

Let’s look at the playoff teams from the past five seasons. Since I’ve already listed the 2008 playoff teams I’ll start with 2007(thanks to Ryan Glass of DRB for helping with the data).

2007:

Team	Players born in August
Indians	4
Angels	4
Yankees	3
Rockies	3
D-Backs	4
Phils	7
Cubs	5
Sox	7

2006:

Team	Players born in August
Mets	0
Cards	5
Padres	6
Dodgers	0
Yanks	4
Twins	3
A's	5
Tigers	2

2005:

Team	Players born in August
Yanks	2
White Sox	3
Angels	2
Red Sox	5
Braves	0
Cards	5
Padres	5
Astros	6

2004:

Team	Players born in August
Braves	1
Cards	5
Dodgers	3
Astros	5
Yanks	2
Twins	1
Angels	5
Sox	3

2003:

Team	Players born in August
Yanks	2
Twins	5
A's	2
Sox	8
Braves	2
Cubs	6
Giants	1
Marlins	4

As you can see from the tables, a wide variety of teams made the playoffs. In 2006 two teams with zero August born players made the postseason. In 2007 and 2006 a team with the lowest number of August born players in their league made it to the World Series. In 2004 and 2005 the Braves had 1 and 0 August players but still won their division. In the World Series it’s been a split the past six seasons, with the Phillies, White Sox and 2004 Red Sox winning with a lesser number of August players than their opponent.

So what can we gather from all of that? Not much it looks like. It seems as though while having a high number of August born players cannot be a detriment, and unlike the junior hockey teams noted by Gladwell, it doesn’t seem like it’s a real indicator of team success either.

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Thanks for the props.

One thing I noticed when looking at the players was that it seemed (completely unscientifically) that a larger proportion of the August babies were pitchers. This would seem to fit the view that the August-born would get more coaching because I consider pitching to be more “coached” than hitting.

by rglass44 on Jan 2, 2009 3:18 PM EST reply actions 0 recs

No Surprise

You start out looking only at MLB players, which is an extremely select group to begin with. Then you split that group between those on playoff teams and those that aren’t and you don’t find any correlation between that and August birthdays. I’d be shocked if you did find any.

I’d suggest two modifications to the study. First, instead of players already in MLB, look at the MLB draft Specifically, look at the last 5-10 years of the draft and identify those players drafted out of HIGH SCHOOL. (You could do a separate study on college players, but I advise against mixing the two. They will dilute any results.) For each draftee, record his draft position and month of birth. Then you’d be able to calculate the average draft position for every month, not just August. After all, if August babies benefit, so should Sept. & Oct. kids, albeit not quite as much. On the flip side, May, June and July births should all be underrepresented in the early rounds.

One other thing to keep in mind. You’re bound to have a lot of August births in any such study, regardless what sport or other activity you’re looking at. That’s simply because August babies are conceived in the winter when it’s cold outside and there isn’t a lot else to do. The important question is not how many there are but how successful they are relative to their peers.

I’m an August birth myself. I have no baseball talent other than the sabermetric kind. But I have been very successful in other endeavors. And I attribute that in part to the fact that the cutoff for each school year was Sept. 1 so that I was always among the youngest in my class. In effect, I had a head start on most of my classmates. That’s exactly the opposite of the youth baseball situation, where August births would be the oldest at each level. I’d be interested to see the results you get.

by fjm235 on Jan 2, 2009 4:07 PM EST reply actions 0 recs

August is the most popular birth month in the US

Followed by July and September.

by rglass44 on Jan 2, 2009 4:40 PM EST up reply actions 0 recs

You're right about August.

But after that there is quite a bit of variation. In 2007 it went July-Oct.-Sep. In 2006 it was Sep.-July-Oct. It always seems to be those 3 months, in some order.

There is consistency on the low end too. In 2007 it went Feb.-April-Nov.-Jan., starting from the bottom. In 2006 it was Feb.-April-Jan.-Nov. Of course Feb. is always low because it’s a short month.

by fjm235 on Jan 2, 2009 5:55 PM EST up reply actions 0 recs

There's apparently nothing to do in November

or October or December. Plus it’s cold. (My wife is due in late June… you do the math.)

http://mvn.com/mlb-stats

by pizzacutter on Jan 3, 2009 10:37 AM EST up reply actions 0 recs

I looked at only MLB players because I was looking at the success of MLB teams

I’ll get to the rest of the post later, but if you read the book he gets into the cutoff dates for schooling as well.

by Erik Hahmann on Jan 2, 2009 4:47 PM EST up reply actions 0 recs

And this only pertains to US born players...

Unless there is a cutoff date around the world. If there is no such thing, then the analysis is flawed (unless care was taken to eliminate all foreign born players).

I’d find out the number of American born players on all those teams, predict the number that were born in August (with the % of births in August) and compare that to the actual number born in August. If there are significantly more players born in August in MLB than predicted, Gladwell’s analysis holds truth in the MLB.

by KMils on Jan 2, 2009 6:46 PM EST reply actions 0 recs

Yes, it's only American born players

And take a look at this. http://www.sabernomics.com/sabernomics/index.php/2006/05/age-cut-offs-and-month-of-birth-in-baseball/

by Erik Hahmann on Jan 3, 2009 10:55 AM EST up reply actions 0 recs

This same study was done about the NFL last year at PFR.

Valentines day is the most successful birthday for NFL QBs. By far.

Even more hilariously, the second best day is February 15th. February 3rd is fourth on the list.

Valentines day has delivered the greatest QB in the history of football (DREW BLEDSOE!!!), Jim Kelly and Steve McNair. Not to mention David Garrard, Jared Lorenzen, Patrick Ramsey and Anthony Wright.

And That Happened: Sports with a Hint of Sarcasm

by philkid3 on Jan 2, 2009 7:19 PM EST reply actions 0 recs

Malcom Gladwell

There’s good money to be made betting against Gladwell. He is quite the buffoon.

by JobiJoba on Jan 2, 2009 10:59 PM EST reply actions 0 recs

Whatever you say.

I wasn’t betting against Gladwell. I read the book and got curious.

by Erik Hahmann on Jan 3, 2009 10:49 AM EST up reply actions 0 recs

High School Success

I could see this having a higher impact on high school kids getting drafted. Being close to a year older in high school would be a greater advantage in your teens than your early 20’s, no?

As a sidenote, a lot of baseball leagues have changed their age dates to the December 31 variety. I know American Legion and Babe Ruth baseball has done this. I’m not sure how USSSA does birthdays, although USSSA might be as shady as the Chinese when it comes to age dates.

by Warden11 on Jan 3, 2009 10:57 AM EST reply actions 0 recs

I'm reading this book too.

In fact, just started it today and devoured the first 100 pages in one sitting, which I almost never do.

At any rate, I felt like there was an interesting note that he didn’t pursue. In theory, the best MLB players shouldn’t be born in August…they should be born between May and July. Those are the players who were talented enough at age 8 to outperform players who were 10-12 months older than they were, then as time went by and the age-gap became less relevant, they grew to become the same size, etc as their rivals, and should surpass them.

I don't specifically articulate my motives, because that wouldn't travel as well as a boo does.

by KLSnow on Jan 8, 2009 7:34 PM EST reply actions 0 recs