In the lab: A deeper look at defensive efficiency

The very best stats are mirror images of each other. Last time we looked at offensive efficiency and it only makes perfect sense to turn around and look at defensive efficiency. When we look at both halves we get a much clearer picture as to how good a team really is and whether there are any hidden gems in there that could make noise come playoff time.

So, if you did not catch that particular article, I would strongly suggest going back and taking a look at it. Essentially, efficiency is rated by taking total runs scored or allowed and dividing it into hits, walks, and hit by pitches. We will make the same adjustment with home runs that we made with the offensive numbers to see what happens. As you might imagine, the Astros are near the bottom of this one as their units have served as mirror images for much of the season. Statistics are accurate coming into play on Wednesday.

Let’s start local and move our way out. The Astros pitching staff has been awful overall on the season, but as we saw in an earlier lab, most of that came in March and April. They are 13th in the American League in runs allowed over the full season, so it shouldn’t be any surprise that they are one of the worst teams in terms of efficiency. I’ll just say that the Athletics numbers are staggering on so many levels, but the rest of the league looks normal with one notable exception.

When I looked at the offensive chart, I noticed that the Rays were not nearly as efficient as they could be. We see the same thing here on the pitching end. They rest near the bottom in efficiency even though their overall record in terms of runs scored says they should be much better. I’m not a betting man, but if I were I might put a wager on them come playoff time because that is a baseball team that’s underlying numbers are much better than they are actually performing.

As for the hometown nine, they are 2nd in walks allowed and first in hit batsman. Thank God for the Angels because otherwise it wouldn’t even be close when we combine those two together. Eight AL teams have surrendered more hits than the Astros. So, when you look at raw ability, they should be in the middle of the pack and that is what we have seen from May 1st on.

As we saw with the offensive numbers, home runs dramatically impacts efficiency, so we should expect to see the same thing on the pitching side. So, what we are doing is simply removing home runs from the total base runners column and from the runs scored column (assuming solo shots for now) to see what happens to the efficiency rating.

The Red Sox and Athletics are really mirror images of each other. Neither is historically bad or good compared to the very best and worst seasons on the bump (2018 and 2022 Astros are at the top since the DH). However, since this is an Astros site, we should focus in on the hometown nine. They are slightly better comparatively when we remove the home runs.

One of the things to come out “Moneyball” was the development of something called the “Beane count”. It was a crude metric where you compared the amount of home runs hit and home runs surrendered along with walks drawn and walks surrendered. In most seasons, if you are on the positive end of both of those then you probably have a pretty good baseball team. The opposite is obviously true as well. So, the Beane count for the Astros looks like this:

Home Runs: 162 for, 164 against = -2 HR
Walks: 411 for, 504 against = -93 walks

These numbers predict that the Astros should not be a good team and when you look at the Pythagorean record you can see that the Astros currently sit at 58-64. For those unfamiliar, the Pythagorean record takes the runs scored and runs allowed and spits out an expected record. The Astros have surrendered more runs than they have scored, so they should not be above .500. Of course, there are any number of factors that could credibly explain why teams overperform or underperform. Some of those tend towards the luck end of the spectrum while others are structural with things like bullpen performance and other factors.

The Beane count is crude and it seems easy enough to say hit more dingers and walk more, but turning things around can be that simple. In the Astros case, they probably need to work on the pitching end of that equation. In particular, being 29th in walks allowed is not acceptable. Adding in being 30th in hit batters is also not a good thing. It will be interesting to see what happens at the end of the year when we look at these numbers again.