Stats Glossary: Taking a look at wRC+


One of the best aspects of baseball is the reliance on statistics to make a point. It’s unlike any other sport. For instance, when you watch football, do you immediately know how many times a wide receiver was targeted, how many receptions he had, and the subsequent ratio? In baseball, many people can recite their favorite player’s slash line, or give you a pitcher’s ERA and WHIP in order to strengthen their argument. But what do they mean?

Yep, still the Yankees best hitter, no matter how you slice it (Image: Rick Osentoski-USA TODAY Sports)

Well, here at YGY we wanted to give people a heads up on how certain stats are used, and why they’re used. We’ll make a page termed “Stats Glossary” for everyone to reference when they see stats like “wRC+” and “xFIP” in our articles. Our own Matt Hunter wrote a series on sabermetrics titled, “Sabermetric Outlook Primer“, which gives you a quick rundown of different advanced stats.

For newcomers to sabermetrics, this could be invaluable. I know we have a few visitors (BIll B, I’m looking at you) who use traditional statistics like batting average, slugging percentage, WHIP, and ERA — there’s nothing wrong with that. We here at YGY feel that traditional statistics do serve a great purpose, but they don’t tell the entire story.

For instance, a player who hits for a .230 batting average, but has a high on-base and slugging percentage may very well be just as valuable to a team with a guy who possess a batting average north of .300, an average on-base percentage, and low slugging. Need an example? Jason Kubel had decent slash line (.253/.327/.506) in 2012. Now compare that to Adrian Gonzalez‘s .299/.344/.463 slash line, and who do you think creates runs at a higher rate for their club? The answer would be they both create the same amount (115 wRC+). Want more? Curtis Granderson‘s slash line .232/.319/.492 netted him a 116 wRC+ rating.

Now if that made little sense to you, let’s go over what wRC+ is and how it’s measured. The acronym stands for weighted runs created, and it’s used to quantify how good a hitter is by the rate at which he creates runs. The purpose of baseball is to score runs, correct? Now, where wRC+ comes into the picture, is that yearly averages are everchanging. Likewise, all ballparks are not created equal — Yankee Stadium, amirite? So, there had to be a way to help measure players against their peers in different leagues and ballparks. That’s where wRC+ comes into play. It takes into account the different ballparks, different leagues, as well as the league average for hitters that year, and spits out an easy-to-read number.

Now, 100 is league average, which is absolute — meaning 100 will always be league average regardless if the statistics surrounding them change year-to-year. Each number above or below that is a percentage point. For example, last season, Robinson Cano was eighth in all of baseball with a 150 wRC+ rating, or he created runs at a 50% higher rate than the league average player. I think we can all agree that Cano (.313/.379/.550) was the team’s best hitter last season. Who would you think was second on the team? Derek Jeter and his excellent .316/.362/.429 slash line is a great candidate. His 2012 campaign resulted in a 117 wRC+ rating, which is great. However, if that was your answer, you’d be wrong. It was actually Nick Swisher and his .272/.364/.473 slash line, which gave him a 128 wRC+ rating.

What gives? Jeter and Swisher had similar slash lines, but Swisher’s slugging percentage is what gives him the edge. Plus, more home runs, obviously means more runs. Simply hitting single after single doesn’t give you the best chance at getting runs, but a home run, well, that’s pretty self-explanatory.

I’m sure this will ruffle a few feathers too, but Jeter ranked 54th in the MLB with a 117 wRC+ rating, however, Mark Teixeira and Curtis Granderson were both nipping at his heels with a 116 wRC+ rating. Why? Because they possess the single greatest run producer called: Home Run Power.

Saying that, home run power isn’t the only part of the equation. Other offensive statistics like batting average, on-base percentage, etc., do play a role. After all, it’s an all-encompassing offensive output metric. Triple crown and MVP award winner, Miguel Cabrera, and young superstar, Mike Trout, both had identical wRC+ ratings (166), which was tops in the MLB (Funny, they were both MVP candidates too). Cabrera had a .330/.393/.606 slash line compared to Trout’s .326/.399/.564 line, but what’s amazing about Trout is that he recorded that in 60 fewer plate appearances than Cabrera and did so hitting 14 fewer home runs. Let that settle in for a moment and truly marvel at Trout’s 2012 campaign, he was spectacular.

Just to give you a quick idea of how valuable these two were to their clubs compared to the league average. They created runs at a 66% better rate than the league average player just with the bat (remember 100 is league average. Think: Brett Lawrie).

It’s a lot to digest, I know. But please consider that this is one of the best metrics to measure offensive output on a yearly basis. That is the exact reason why we include it in many of our articles. It’s not a foolproof stat, nor is it one that will end discussions. But, including the slash line along with the wRC+ rating helps paint a clearer picture rather than just giving you just the hitter’s slash line by itself. We include both because the slash line is still a very powerful statistic and can sometimes give you a snapshot of how a player is hitting, but it doesn’t give you very much context with regards to other players, which is exactly what wRC+ does.

This is the first of a few trips in Sabermetric land. Hopefully, this helps you understand a very powerful statistic, and how to use it correctly. We’ll be bringing you other advanced statistics and how the Yankees fit into them soon. Until then, embrace wRC+, it’ll serve you well!

Stats courtesy of FanGraphs. Also, the wRC+ metric is a Tom Tango creation