Great Pitching Beats Great Hitting…or Does It?

The common wisdom is that great pitching beats great hitting. This line of thinking becomes especially true as the calendar turns towards October and the rubber meets the road.

But is the “great pitching beats great hitting” theory more than just a theory? Do teams with better pitching tend to win more playoff games? Is October baseball dominated by the teams with the best pitching staffs? Is it true that pitching wins championships?

We are going to put the conventional wisdom to the test by looking back at playoff data all the way back to the 1920s. We’ll look at whether or not pitching talent or hitting skill is more predictive of winning in the baseball playoffs. We’re going to determine once and for all whether great pitching beats great hitting.

The Theory of Why Great Pitching Beats Great Hitting

We’ve heard it countless times. Teams reliant on streaky offense or home runs “won’t make it through October”. This sentiment is typically championed by the grizzled old guy at the end of the bar that seems to be there every time you walk in. But why does he think this way?

There are many ways to justify why great pitching beats great hitting. My best guess is that it comes down to consistency and controlling the game.

Offense in every sport has a reputation of being inconsistent. In the NBA, a similar idea exists: live by the three, die by the three. The logic is that you can take a lot of three pointers but eventually your luck will run out and you’ll fail, kind of like the 2018 Houston Rockets. In Basketball, though, this sentiment is regarded by analysts as a myth. It isn’t true, its just a nice saying.

In baseball, one way the inconsistency of offense manifests is in homerun dependent teams. Some teams score a disproportionate amount of their runs via home runs. This playstyle might be inconsistent. The last thing you want in the playoffs is for the home run hitting to disappear. T

Pitching, on the other hand, might be more consistent. It takes only one pitcher having a good night to have “a good pitching night”. It takes multiple hitters having a good night to have “a good hitting night”.

There are many ways to talk about why great pitching beats great hitting. But the problem is that none of these theories or gut opinions necessarily translate to the real world. In the standard Data Jocks’ way, we’re going to use stats and data to get to the heart of the matter. Does pitching win championships?

Studying October Baseball with Stats and Data

The first step in studying an analytics problem is deciding on the correct stats to use. Then, you need to figure out how to put the stats together in the correct way to tell the story you want to tell.

For us, we need to pick one stat which is representative of a team’s pitching and one which is representative of a team’s hitting. There are many choices. For example, I’ve written about wRAA and wOBA before and why they’re great at measuring an individual hitter’s prowess. I’ve also written at length about WHIP and ERA for pitchers.

In this analysis, though, we want to be able to compare across multiple years. We also want our stats to be easily interpretable. For this reason we’re going to use OPS+ and ERA+ to measure how good a team is at hitting and pitching, respectively.

OPS+ is a variant on on base plus slugging. Normal OPS is a mix of on base percentage and slugging percentage that fairly accurately weights the relative value of different types of hits. OPS on its own is a fair measure of a player or a team’s batting quality.

ERA+ is a variant on earned run average. ERA is a measure of the most fundamental pitching stat: the amount of runs a pitcher was responsible for giving up.

Both OPS+ and ERA+ are slight augmentations of their underlying stats (OPS and ERA) where the results are normalized relative to league average. In both “+” variants of the stats, the underlying data is normalized so that a league average team has a score of 100. Values larger than 100 correspond to above average teams.

Using these normalized stats let us compare consistently across different areas to look at long term trends to see if good pitching beats good hitting.

Initial Looks at The Data

First, let’s try to get a sense of what the stats actually look like. A histogram is a valuable tool to see the rough shape of the distribution of the data. We’ll start by showing the OPS+ of the winners and the losers in every playoff series.

Notice first that the distributions are very similar. They are both centered a bit above 100 (this is expected, league average is 100 and playoff teams are above league average). They also both have a similar spread.

However, these two overlaid histograms show that the winners tend to have a slightly higher OPS+ than the losers. This is evident because the blue distribution is more visible “to the right” of the orange distribution. This is, of course, expected. Teams with better offenses tend to win series more often. What happens when we look at ERA+?

The ERA+ plot shows largely the same thing. Playoff teams tend to have a slightly above average pitching. Moreover, because the blue distribution is shifted a bit to the right, it means that winning teams tend to have a slightly higher ERA+. But it is close!

This is an interesting way to look at the data, but it doesn’t answer our question of whether great pitching beats great hitting.

A Deeper Look at the Data

In order to better answer the question of whether pitching wins championships or hitting wins championships, we need to look at win percentage. Our first step was to look at how the probability of winning a game varies with a team’s OPS+ and ERA+.

The plot below shows win probabilities conditioned on OPS+ and ERA+.

My first instinct and first conclusion when looking at this plot is that “I can’t tell what it says”. No matter what the ERA+ or OPS+ value, the team’s winning % hovers right around 50%. There is some hint on the right hand side of the plot that better OPS+ values lead to teams winning more, but I wouldn’t feel comfortable calling this a trend.

So far, our study of whether or not great pitching beats great hitting hasn’t really given us any answers. In the next section, though, we look at the data in one last way that makes the trends quite clear.

Looking at ERA and OPS Margin to Predict Playoff Winners

In the previous section, there was very little trend in the data. Higher OPS+ and ERA+ values didn’t really lead to higher probabilities of winning any individual game. This is because we failed to look at the quality of their opponent in making our conclusions.

For example, it doesn’t matter if someone has a 105 ERA+ value if their opponent has a 110+ value! The same is true for OPS+. The stats alone aren’t predictive of who will win a game. Rather, it is your stats compared to your opponents’ that matters.

We ran the same numbers as before using relative stats instead. We looked at every series in baseball playoff history. For each one, we recorded the difference between the two teams’ OPS and ERA values. Then, we looked at how bigger or smaller differences translated to higher and lower probabilities of winning.

Doing things this way makes the trends much, much clearer.

On the x-axis of the above plot is the margin in one team’s stat versus their opponent. A value of 40 for the orange line means that a team had an OPS+ 40 points higher than their opponent. A value of -20 on the blue line means a team had an ERA+ 20 points lower than their opponent.

This data shows reasonably clearly that teams with a large OPS+ margin have a higher winning percentage than teams with a large ERA+ margin. This is seen by the orange curve being above the blue curve on the right side of the graph.

To translate this, being 30% better in OPS+ translates to a much higher playoff winning percentage than being 30% better in ERA+. I think you can see where this is going…

Does Great Pitching Beat Great Hitting?

The data as I’ve analyzed it says no. Great pitching does not beat great hitting.

Why Not?

In fact, quite the opposite is true. Teams with good offenses are much more likely to do well in the playoffs than teams with good defenses. Higher OPS+ values lead to better winning chances than higher ERA+ values.

Why might this be the case? Why is it that the answer to “does pitching win championships?” a reasonably definitive no. I want to go back to our discussion of consistency.

A team with good hitting has 9 good hitters. A team with good pitching has 4 good pitchers and only 1 controls most of the game on any given night. Consider what happens if your best player has a bad game.

If your best player is a hitter, then you probably only lost 1/9 of your hitting advantage. If your best player is a pitcher and they have a bad game, your game is over. A hitter underperforming can’t lose you the game the way your ace underperforming can.

In this way, pitching can be much more volatile. This is just my guess as to reason behind the counter-intuitive phenomenon that hitting is more important than pitching in October baseball.

Or, let me say that another way. Next time you hear someone say great pitching beats great hitting, you can respond confidently that actually, on the contrary, great hitting beats great pitching in the playoffs.