Snell: “I’ve got a question for y’all”
Snell: “On the board it said ‘Carp wRC+’ What does that mean?”
Broadcaster: “I have no idea”
Snell: “I don’t either”
Broadcaster to other Broadcaster: “Do you have anything?”
Broadcaster: “Where’s it at? What do you see?”
Snell: “So, no it’s not up there anymore. When he was up last…”
Broadcaster: “Weighted Runs Created, I think it is.”
Snell: “What’s the plus?”
Broadcaster: “ahhhh, plus. It means it’s a plus. I have no idea.”
Snell: “And what does that mean?”
Broadcaster: “yea, I don’t know. I’m going to be honest with you.”
Snell: “and it said it was Judge and then him, for all of baseball.”
Broadcaster: “Wow. So, it’s gotta be a good thing.”
Snell: “I don’t know what that is.”
Broadcaster: “I don’t know either.”
Snell: “There’s so many new things, I just don’t know.”
And in that moment comes the inspiration for my weekly Analytical Anonymous article.
Weighted Runs Created…Plus
Weighted Runs Created Plus (wRC+) is a statistic we use in fantasy baseball which attempts to credit a hitter for the value of each outcome (single, double, etc.) rather than treating all hits or times on base equally, while also controlling for park effects and the current run environment.
wRC+ is scaled so that league average is 100 each year and every point above or below 100 is equal to one percentage point better or worse than league average. In theory, this makes wRC+ a better representation of offensive value than AVE, RBI, OPS, or WOBA.
One look at the formula for wRC+ probably explains why this analytic is not on the tip of everyone’s tongue:
wRAA/PA = Weighted Runs Above Average/Plate Appearance
League R/PA = League Runs/Plate Appearance
wRC/PA = Weighted Runs Created/Plate Appearance
Park Factor = Observed effect based on events in a selected park
Let’s walk through the calculation.
As the acronym implies, wRAA/PA measures the number of runs above average a player contributes to his team at the plate per plate appearance. Another way to calculate wRAA/PA is to take a player’s wOBA minus the league wOBA, then divided by the wOBA scale. The wOBA scale can be found on the FanGraphs site.
Next, you need League R/PA, or the league average runs per plate appearance. You can either calculate it (MLB runs divided by the total number of plate appearances during the season) or better yet, look it up (also easily available on the FanGraphs site).
Now, how about we take a very brief look at Park Factor.
Park Factor is one of those parameters most of us probably understand better intuitively than numerically. In fact, I find it best to let someone else quantify the subtleties of this factor. Here’s a snippet from baseball savant listing Park Factors for the past 3 seasons:
Lastly, we need wRC/PA. wRC is based on wOBA. Here’s the formula:
Let me cut this off right here!
By now, it must be painfully obvious that you can easily go down a rabbit hole by doing these calculations on your own. Do yourself a favor and leave it to someone else. These days, when all these values are so easy to look up, it’s much more important to know what to do with a statistic than how to calculate it. Trust me!
Getting back to wRC+, you’re probably asking, “Why would some brainiac come up with a baseball analytic like wRC+?” That’s really not a bad question at all.
The objective of wRC+ is to quantify run creation and normalize it so we can compare players who play in different ballparks or even different eras.
Remember with wRC+, we’re trying to measure a batter’s value using a cumulative statistic that credits a player for total production rather than a per at bat basis. It combines analytics that credit a hitter for how valuable each particular action truly is with the counting stats that give players credit for producing at a given level over a larger number of PA.
Clear as mud, right?
Let’s look at some numbers and see if we can make some sense of it that way.
The table above lists the top 20 in wRC+ for 2022. The full list is comprised of 130 qualified hitters (> 505 PA) over the 2022 season.
It’s no surprise to see many of the top HR hitters on this list since this is the easiest way to “create” a run. You’ll note both Yandy Diaz and Jeff McNeil make the top 20 despite only 9 HRs each. A closer look at their numbers shows both players ranked in the top 5 for all of baseball in K% and Diaz also ranked in the top 5 for BB%. Just as the analytic is supposed to do, these players are being credited for getting on base and creating opportunities for runs.
By setting the threshold at 150+ PAs, the full list of players now includes over 400 (417 to be exact). Here then is the “new” top 20:
We found it! By opening it up to 417 total players, only 6 additional players crack the top 20, including Matt Carpenter at the top of the heap.
So, we’ve solved the mystery of the Padres scoreboard. It turns out those crafty scoreboard operators cherry-picked the wRC+ data to put their guy in the stratosphere with Aaron Judge. Does he belong there? Perhaps an argument can be made both ways. One thing is for certain though, most fans at the ballpark that night also didn’t really know what wRC+ meant either.
At least the Broadcasters probably got something right in this conversation with Blake Snell. Most Padres fans likely echoed their statements on wRC+, “I have no idea” and if Carp’s wRC+ is up there with Judge, “it’s gotta be a good thing.”
Before we call it a day, let’s come to the present and take a quick look at the 2023 wRC+ data after the first month. For note, I made the cut at 100 PAs, placing 148 players on the list. Here are the current top 20 (thru Tuesday night’s games):
This list is definitely a who’s who of players that are excelling in the early season. Quite a few of the names would be expected but there are many surprises as well. We’ll keep an eye on this throughout the season to see how the numbers ebb and flow.
So now, if you’re at a ball game and those slippery scoreboard operators throw up a stat like wRC+ without context, you’ll be prepared to call it out!
As always, keep sifting through the number. That’s where you find the gems!
Follow me on Twitter: @Derek_Favret.
Until next time, my friends!