Well, we certainly got a taste of what a severe pitching regression would look like the last three days, didn't we?
Let's keep things in perspective, though. This is no time to conclude that the pitching is going to slip to such an extent that it performs at league average or worse the rest of the season. In stats-speak it was just a small correction; in baseball lexicon it was just a few rough outings. No time to panic.
Deep into last night's game, around the same time that our "humble correspondent" descended "into confusion," I turned off the TV, grabbed a frosty mug and made my way to my office, where I was determined shake off the torpor of the evening the best way I know how: IPAs, bluegrass and baseball statistics.
Having had my fill of watching the "(return to the) Mean Monster" have its way with the Pirates' pitching and defense, I wondered what he might have in store for the Pirates offense. In other words, what will the (hopefully) inevitable offensive regression to the mean look like?
I had already done some work in this area in the "Return To Average" series. This time I wanted to sharpen that analysis by cleaning up some of the expected plate appearance predictions and place more emphasis on the predicted rate statistics. Rate statistics give us a better feel for what the offense will look like if things work out as expected. Here is what I did:
- Again using the ZiPS Projection system at Fangraphs, I downloaded the Pirates "Updated" ZiPS projections to Excel. (Updated ZiPS are projections of each player's end of season statistics based on what they were expected to do, revised by what they have done so far. More here.)
- I excluded players who are not expected to make large contributions for the rest of the season (Yamaico Navarro, Gorkys Hernandez, etc.)
- I calculated the aggregate offense we can expect from the remaining core group of players going forward - Jones, Walker, McCutchen, Barmes etc. (If you want a complete list I will provide one, but my guess is that we all know who they are.)
- I subtracted the aggregated updated projections of the core group from their current aggregated statistics to get rest of season (ROS) expectations.
- For the expected performance of non-core players and pitchers, I pooled their current statistics together and multiplied them at the current rate for the rest of the season.
Here is what I found:
Key: Current=current rates; ROS=rest of season; End of Season=end of season rates
(ROS wRC edited. Thanks JRoth95)
(Edited: Thanks JRoth95)
According to the way I designed my projections, for the rest of the season the Pirates offense will produce at a slash rate of .242/.303/.377 with a .680 OPS and .300 wOBA.
So, what will this type of offense look like? I don't want to tell you this part. Indeed I shouldn't. But I think at this point I have to. I have an obligation. Here it goes. Looking at all offenses since 1980, the closest comparison to the projected offense we will see over the next 100 games is the 2010 Pirates offense. Over the course of a 162 games that year, '10 Pirates slashes were .242/.304/.373 with a .678 OPS and .300 wOBA.
Ugh. That is it for now. I think I'm going to go back to my study.