First Pitch: Can We Trust The Pythagorean Record?

Ed Giles had two updates on Twitter today that I thought were interesting in relation to the Pirates’ Pythagorean record. We see that record thrown around all the time as evidence that the Pirates aren’t as good as their current record. But how much stock can we put in the stat?

Like any other stat, this one has to be put in perspective. First, it serves a good purpose. It tells what the team has done, and provides a great idea of what the team will do going forward. Prior to their 4-1 win tonight, the Pirates had scored 239 runs, and gave up 249. That amounted to an expected 33-35 record. Thus, their 36-32 record was lucky. And that gap has been closed with their huge win against Minnesota on Thursday.

Also like any stat, sample sizes have to be considered. In one of the tweets by Ed Giles, he pointed out that the Pirates had a -8 run differential in April, -21 in May, and +19 in June. That’s +23 after tonight’s win. So what does this tell us? It says the Pirates were a little below even in April, horrible in May, and have been great in June.

What does all of this tell us going forward? Will we see the horrible May version? Will the strong June version continue? Will they be like the April version — bad, but not horrible?

That’s where the other tweet by Giles comes in. He pointed out the monthly run differentials last year, which amounted to +6 from April through July. But then in August the Pirates were -54 and in September they were -44.

I could point to that and say “you can’t trust the Pythagorean record alone” and I’d probably be right. But I’d probably need to explain why. Everyone saw the Pirates’ pitching staff for what it was last year. They were overdue for a regression, and it just so happened that they did a 180 in the second half. So even though the run differential was positive, they weren’t expected to maintain their pace.

So how does that relate to this year? The pitching is expected to regress some, but not nearly as much. This is still a strong staff, and the weak points (Kevin Correia, Brad Lincoln) can be addressed with internal options (and should be addressed by those options sooner, rather than later). The hitting has been bad. I don’t think it’s as bad as May, and I don’t think it’s as good as June.

The Pirates have a lot of streaky hitters and one pretty consistent hitter in Andrew McCutchen. I think we’ve seen a lot of extremes this year with that combination. At times all of the hitters have been cold, except McCutchen. Right now we’re seeing a lot of the hitters on hot streaks, leading to the huge offensive output. This won’t continue, but neither will the “everyone is cold at the same time” trend.

I think the Pirates can expect a few hitters to get hot, McCutchen to keep hitting, and the pitching to regress a bit, but still be a strong asset. Add a bat to that next month to help out the offense, and I don’t see why the Pirates can’t continue putting up a positive run differential. It won’t be anything like their June differential so far, but it could amount to something that would justify a decent record from here on out. And considering their easy schedule over the next month and a half, I don’t think it would come as a surprise if they had a positive run differential.

The run differential tells us that the Pirates shouldn’t be sitting here with a winning record, and probably won’t continue winning if they play the way they have to date. But that’s the key. There’s no guarantee that they will continue playing the way they have, just like there was no guarantee last year after finishing with a positive run differential after the first four months. An easy schedule, adding a bat, and getting a few hitters hot at the right times could easily give this team a positive run differential, and maybe a Pythagorean record that justifies their actual record.

Links and Notes

**The Pirates won 4-1. Kristy Robinson’s notebook looks at A.J. Burnett finding the joy in baseball again.

**Prospect Watch: Strong starts from Justin Wilson and Clay Holmes, plus Quincy Latimore’s power surge continues.

**Prospect Notebook: Recapping the pro debut from Holmes, and other State College notes.

**Pedro Alvarez is seeking a consistent hot bat for the Pirates.

**As the trade deadline approaches, the Pirates are looking to improve all areas.

**Randy Linville had a good article on the Pythagorean record, talking about how the Pirates need to steal ten wins.

**Pat Lackey wants to believe in the 2012 Pirates.

Tim is the owner, producer, editor, and lead writer of He has been running Pirates Prospects since 2009, becoming the first new media reporter and outlet covering the Pirates at the MLB level in 2011 and 2012. His work can also be found in Baseball America, where he has been a contributor since 2014 and the Pirates' correspondent since 2019.

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