Know Your Stats: Weighted Runs Created Plus (wRC+)

In last week’s installments of the widely-beloved “Know Your Stats” series, we looked at both OPS/OPS+ and wOBA. Today we already looked at wRAA and will now cover wRC+.

Of all the popular offensive statistics publicly available in the baseball world, Weighted Runs Created Plus (wRC+) may be the gold standard. It combines the corrections to batting average, OBP, and slugging made by wOBA with the convenience of a park-adjusted index.

wRC+ is basically rooted in wOBA, but there is a multi-step process involved in getting it from start to finish. If you don’t remember from last week, wOBA is a rate stat just like your traditional BA/OBP/SLG, except it corrects each of those stats’ faults.

To get from wOBA to wRC+, the former is first turned into wRAA. That is done through the simple process I outlined this morning.

Once we get wRAA, it is turned into wRC+ through the following formula:

This looks way more confusing than it actually is, but I’ll explain what it does in simple terms. It converts wRAA from a raw total into an index stat like OPS+, where 110 is ten percent better than league average and 90 is ten percent worse.

Like OPS+, wRC+ is league and park adjusted, meaning it makes it easy to compare players from different eras and in different parks.

More thoughts

If you are thinking about trying to correlate wRC+ to runs scored, don’t. If we were trying to correlate with runs scored, we wouldn’t be adjusting for anything.
If choosing between OPS+ and wRC+, choose wRC+. The difference probably won’t be very significant, but both are widely available and wRC+ is a bit better.