Right handed power: A potential dividing line

Right handed power. Some organizations claim they desire it; some analysts decry this desire. "Right handed power, you say? Fellows like Mark Trumbo and Nelson Cruz prove that right handed power isn't all that it's cracked up to be!" There have been many words written about Cruz and Trumbo at this website and others. This is partly because Cruz is a free agent this offseason and Trumbo was traded, but there were other words written about how these two players support the case that right handed power is overrated.

Well, the second kind of words stimulated thought; specifically, what is right handed power? I set about investigating this question using standard deviations.

Using isolated power (ISO) as the measure of power and looking at 2013 only, the thinking was that those right handed batters who are at least one standard deviation above the mean ISO can be considered "true" power hitters, whereas hitters who have merely an above average ISO, but not at least one standard deviation above the average, can be considered hitters with power.

In order to get a list of batters with a stable ISO, the sample was restricted to right-handed hitters with at least 550 PA. In this sample, there were 51 hitters; the mean ISO* was .166, and the standard deviation was about 0.053. Therefore, in order to be one standard deviation above the mean and considered a "true" power hitter, a hitter must have had an ISO of at least .219, which falls between "Great" and "Excellent" on FanGraphs' ISO chart. There were 11 such hitters of the 51. In a happy coincidence, there is in fact one hitter of the 51 whose ISO was exactly .219: MARK TRUMBO**! Other hitters who were right around a .219 included Marlon Byrd, Carlos Gomez, and Mike Napoli. Miguel Cabrera, in his awesomeness, was the only one who was at least two standard deviations above the mean.

On the whole, those hitters with at least a .219 ISO were excellent offensive contributors with an average 139 wRC+. However, this is where selection bias rears its ugly head. The 550 PA cutoff eliminates any players who simply weren't good enough to accrue 550 PA and would have brought the results down. For instance, Jeff Keppinger had a .064 ISO and a 60 wRC+ in 451 PA. However, it also eliminates any extremely high and potentially unsustainable ISOs in a smaller number of PA, like Hanley Ramirez's .293 ISO and 191 wRC+ in 336 PA. It is possible that selection bias may not have a strong effect. If it does, the results are probably biased upward in this sample.

I suppose a conclusion from this investigation is that right handed power, as defined by standard deviations, is rarer than we might think, but it also provides excellent production in general. Perhaps ball clubs are not entirely mistaken for going after some power from the right side, but this is only one year of data. Another conclusion is that Mark Trumbo, with his .219 ISO and only 106 wRC+, seems to be full of sound and fury, but signifying nothing.

*The ISO is normally distributed in this sample, so the mean is appropriate

**Perhaps we can call the minimum amount of power necessary to be called a right handed power hitter the "Trumbo Line"

. . .

All statistics courtesy of FanGraphs.

Kevin Ruprecht is a contributor for Beyond the Box Score. He also writes at Royal Stats for Everyone. You can follow him on Twitter at @KevinRuprecht.