TheLines has prepped some primers on key metrics that can aid your daily handicapping. After several looks at how we can evaluate pitchers using a variety of metrics, we’ll shift our attention to offense. Specifically, let’s take a look at wRC+ (weighted runs created plus).
So, what is wRC+ and how can you apply them it MLB betting?
What Is wRC+?
Again, wRC+ stands for weighted runs created, with the plus signifying that the stat has been scaled to league averages with 100 representing average. That is, numbers more than 100 represent above-average offense and numbers below 100 represent below-average offense.
Furthermore, each number either above or below 100 tells you how the players or team’s weighted runs created compares to league average in terms of percentage points. So, a team with a wRC+ of 120 creates offense at 20% above the league average.
Most teams will land within 20% of the league average but individual players can land wildly above or below that. For example, perennial MVP favorite Mike Trout boasts a whopping 172 wRC+ for his career, meaning he creates offense at a clip of 72% better than league average.
While knowing a hitter’s offensive talent level can be useful, we’re primarily concerned with wRC+ on the team level.
Other key baseball metrics
Why Is wRC+ Useful?
I think the FanGraphs resource page puts it best:
“wRC+ is the most comprehensive rate statistic used to measure hitting performance because it takes into account the varying weights of each offensive action and then adjusts them for the park and league context in which they took place.”
The latter part is a key factor. Simple counting/ratio stats and even an advanced stat like wOBA (weighted on-base average) won’t factor in league and park effects. For example, Rockies players are going to appear more talented than they really are because playing half of their games at Coors Field will inflate these stats.
Thus, if we want to get a clear picture of the quality of a team’s offense, wRC+ is a great place to look.
Using wRC+: A One-Stop Shop For Team Offensive Strength
So, how can we find wRC+ and how can we apply it to betting? Say you are looking at the Opening Day matchup between the Astros and Angels. You see the starting pitchers are Framber Valdez and Shohei Ohtani, and you’ve done your homework on them.
What about the offenses?
First, head over to baseball resource and content site FanGraphs. We’re going to use last year’s numbers just for example’s sake because obviously nobody has accumulated any stats for us to analyze in 2022. Hover over “Teams” at the top and click “2021” under Team Batting Stats. Scroll to the stats table and click the “wRC+” column. That will sort in descending order.
We can see Houston had the best offense in the league last year by a fair margin with 116 wRC+. The LA Angels checked in down at 17th with a 94 wRC+. So, we can expect Houston to produce a fair bit more offense than LA.
If you want to get a little more granular (and you should), you can check out how these offenses do against relevant-handed pitching. Since Valdez is left-handed, find “vs L” under the splits menu above, then click “Advanced.” You’ll find wRC+ on the far right side of the table now and you can see the Angels fared significantly better against left-handed starters with a 101 wRC+.
Use wRC+ To Evaluate Team Offensive Strength
Trying to project how many runs a team is going to score in a given game obviously involves more math than this, but if you just want to get a simple, all-in-one gauge of a team’s offensive strength, wRC+ should be your go-to stat. It eliminates extraneous factors like ballparks and distills team offense down to an easy-to-digest number.
The trick will come in deciding when to start trusting the number you’re seeing. You can’t just look at the teams’ offenses after the first week and decide these reflect team talent levels. It’s going to take some time for numbers to settle and normalize at something stable. So, make sure you give some weight to your prior estimates of the teams as well.
And don’t forget to apply splits when applicable. We went over this from the pitching side of things here, but the principles apply to offenses as well. Try to find offenses that will perform well in a given matchup and see if the market hasn’t given them appropriate respect.