It's just about playoff time in Major League Baseball, which means one thing: You're about to hear the old "pitching wins championships" adage a few million times or so during the month of October.
Rather than just take that typical commentator claim at face value, we decided to dig a little deeper to see if there's really truth to it or if it's just something broadcasters say in order to sound smart.
To get a better idea of whether pitching or hitting wins World Series, we looked back at the past 10 winners from 2003 through 2012 and found where they ranked during the regular season in various and relevant hitting- and pitching-related categories.
The six hitting statistics you'll see in the tables to come are runs scored (RS), batting average (BA), on-base percentage (OBP), slugging percentage (SLG), on-base plus slugging percentage plus (OPS+) and weighted on-base average (wOBA).
Meanwhile, the six pitching metrics considered below are runs allowed (RA), earned run average (ERA), earned run average plus (ERA+), fielding independent pitching (FIP), walks and hits per inning pitched (WHIP) and strikeout percentage (K%).
Let's get to the data, starting with how the World Series winners over the past decade performed with the sticks.
The Case for Hitting
As you can see by the last row, the average championship club over the last 10 seasons scored almost 800 runs while slashing .270/.340/.434 and posting a solid wOBA of .336. Their average OPS+ of 103.5 means they were 3.5 percent more productive in OPS than the league average.
Another good way to break down these numbers is to highlight how many times these teams placed in the top 10 in a statistic. Interestingly, all six hitting metrics had exactly five top 10 showings, suggesting some level of consistency.
And before moving on, realize that these teams finished in the bottom 10 in any of the above hitting categories only twice in their championship seasons—the 2005 White Sox in OBP and the 2008 Phillies in batting average.
The Case for Pitching
Now that the offensive numbers have been laid out, here are pitching performances by title teams from 2003 through 2012.
Again, let's review the final row to get a better sense of things. On average, the last 10 World Series winners gave up fewer than 700 runs while sporting a 3.93 ERA and 1.31 WHIP, as well as a commendable 4.08 FIP and 18.5 strikeout percentage. Their collective ERA+ of nearly 110 means they were 10 percent better than league average in ERA.
Repeating the exercise from before is a bit more intriguing on the pitching front, as each category has at least five top 10 showings, with WHIP having exactly that amount. As for the other five metrics, though, ERA, ERA+, FIP and K% all saw six top-10 performances, while seven teams who won it all managed to be in the top 10 of fewest runs allowed.
It's also worth noting that there were only six instances in which one of these clubs finished in the bottom 10 of a particular pitching category—the 2012 Giants in ERA+ and FIP, the 2011 Cardinals in strikeout percentage and the 2006 Cards in ERA+, FIP and strikeout percentage.
Alas, when determining whether hitting or pitching really wins championships, the numbers are not overwhelmingly conclusive in favor of either.
The arms, though, have a stronger case than the bats, as the average ERA+ of the World Series winners is slightly better than their average OPS+. These teams also had more total top 10 showings in the pitching categories than in the hitting ones by a score of 36 to 30.
Of course, none of this is to say that a team that is big on the bats during the regular season can't be the last team standing. For instance, the 2011 Cardinals and 2009 Yankees both ran the table primarily on the strength of their sticks.
But it can be done the other way, too. The 2010 Giants and 2005 White Sox more or less won rings by riding their pitching staffs.
If there's one takeaway in all of the above, perhaps it's this: While at least one of the past 10 World Series champs ranked in the bottom half in each of the six hitting categories explored, not a single one finished in the bottom half in runs allowed, ERA or WHIP.
Should they make it in on a Wild Card spot, that might spell doom for this year's Indians, who are on the fringe in runs allowed (17th) and ERA (15th) and on the outs in WHIP (23rd).
The only other contender who's on the fence in one of these three areas? The Red Sox, whose 1.30 WHIP is currently 14th-best in the majors this year, but could fall into the bottom half with a bad outing or two in the final games.
Just something else to watch between now and the end of October.