Good pitching beats good hitting all the time?

You've heard it before: Good pitching beats good hitting all the time. Pitching and fielding wins pennants. Pitching is 90% of the game. So, I wanted to examine the relative importance of offense and pitching/fielding in getting into the playoffs. This sort of thing has been done before by Bill James, Pete Palmer, Baseball Prospectus and others but I haven't seen it done for a while so I wanted to revisit the question.

I didn't want to do a complicated analysis involving multiple regression or anything like that . I wanted to keep it simple and intuitive. What I did was rank every team each year since 1988 (except the strike year of 1994) based on offense (runs scored) and defense or pitching/fielding (runs allowed). I then classified each team's offense as good, OK or bad based on their rank. If they finished in the top third of the league, then they were good. If they finished in the middle third, then they were OK. If they were in the bottom third, they were classified as bad. I classified team pitching/fielding the same way based on runs allowed.

Crossing the offense classification (good, ok, bad) with the defense classification (good, ok, bad),
I got the nine categories (good offense and good defense, ok offense and good defense, etc) shown in Table 1 below. For example, the 2007 Indians were sixth in the American League in offense in 2007 and third in defense so they went into the OK offense/good defense category.

There were 128 playoff teams since 1988 and 47 of them had both strong offense and defense. The next most frequent categories were OK offense and good defense (35) followed by good offense and OK defense (25). The other combinations were less common.

What can we conclude from this data? More than a third of the teams which made the playoffs had both good hitting and pitching/fielding so it's important to try to build both components. Second, it IS more common for an OK offense/good pitching and fielding team to make the playoffs than a good offense/OK pitching and fielding team but it's not THAT much more common. There is more than one way to build a team for post-season. What about teams that have bad offense/good defense or good offense/bad pitching. Well, neither is a particularly good way to build a team but one is not worse than the other.

Table 1: Offense and Defense of playoff teams (1988-2007)

Offense	Pitching/Fielding	Number	Percent
Good	Good	47	36.7
OK	Good	35	27.3
Good	OK	25	19.5
OK	OK	7	5.5
Good	Bad	6	4.7
Bad	Good	7	5.5
Bad	OK	1	0.8
OK	Bad	0	0.0
Bad	Bad	0	0.0

The next question you may have is whether good pitching/fielding was more important for teams that made the World Series. Table 2 below is the same as Table 1 except it only includes teams that made the World Series. Again, the most common classification was the good/good category - 18 of the 38 teams. The defensive side of the ball did seem a bit more important for World Series teams as 13 teams had OK offense and good defense as opposed to just 5 teams with good offense and OK defense.

So, we can conclude that a lack of pitching/fielding is worse than a lack offense for teams aspiring to get into the World Series. However, being strong in both offense and pitching/fielding is even more important for winning pennants than it is for getting into the playoffs.

Table 2: Offense and Defense of World Series teams (1988-2007)

Offense	Pitching/Fielding	Number	Percent
Good	Good	18	47.4
OK	Good	13	34.2
Good	OK	5	13.2
OK	OK	2	5.3