Happy New Year everyone! It's the first Staturday of 2020 and today we will be learning my favorite offensive stat: Weighted Runs Created Plus or wRC+ for short.
Before we get to the "+" part, there is a stat called Weighted Runs Above Average and it uses wOBA which we just learned about last week. Here is the calculation for wRAA:
You do not have to memorize this, it's merely here just so you know that there is a formula to it. The average scale for this stat is 0 but normally you will not see this stat listed on Fangraphs or Baseball Reference.
Instead you will find our stat of the week: wRC+. The formula is:
So wRC+ is based on wOBA which is already a great offense stat for evaluating players. It then also takes into account park factors (hitting in a hitter friendly park versus a pitching friendly park), and it removes offensive stats from pitchers because they drag down offensive stats.
Much like OPS+, wRC+ creates a league average number, 100, that gives us a reference to use when evaluating a player. Anything above 100, that player is better than average.
Here is an example between wRC+ and wOBA using two of the best hitters in baseball last year, Mike Trout and Christian Yelich. In 2019, Mike Trout had a wOBA of 0.436 and Yelich had a wOBA of 0.442. Was Yelich the better hitter? Using wRC+, Trout had the better offensive season, 180 to 174. How? Well wRC+ factors in the ballparks and Trout plays the majority of his games in a pitcher friendly park while Yelich plays his at a hitter friendly park.
One more example for you but this time evaluating an individual player against himself: Jason Heyward.
We see here that Heyward was usually around 20% better than average with the bat from 2010 through 2015 (he battled injuries all through 2011). He also played Gold Glove defense in RF, something we have seen with our own eyes during his time with the Cubs. This makes it somewhat easier to understand why Theo gave Heyward $184 million over 8 years. He thought he was getting a great defender who just happened to be a great hitter as well.
But we know the story with Heyward. The offense fell below flat and he was actually 28% below average in 2016. Since then he has improved each season and is now an average hitter for the Cubs. He may never become that hitter with a wRC+ of 120 again but it makes him easier to play if he can give you anything close to average.
Since this is our last offensive stat for the offseason, I will try and compare the stats we learned about to some baseball terminology. OPS and OPS+ are like a guy in Single-A; they aren't the best but they provide some value to the organization. wOBA is the ballplayer flirting between the big leagues and AAA. He's good but there is just something that is missing. wRC+ is the big league ball player of the bunch.
Next week we will turn to pitching and find out what is and how to use FIP and xFIP.