Hosmer And Butler: Duo’s Power Developed As Expected


In my debut article for Beyond The Box Score, I rolled out a new analytic – CAL, or Comparison and Likeness. In a nutshell, CAL is a player classification system that attempts to put minor league numbers in a more proper context by providing a list of player comps and conclusions can be gathered from the evidence provided. It’s a system based off of Bill James’ Similarity Scores.

Royals Review, another SB Nation member, will be running a piece about how past, current, and future Royals looked according to CAL in the next day or two. But I wanted to highlight something incredibly interesting with two of KC’s top young bats – Eric Hosmer and Billy Butler.

A lot’s been made – especially this season – about the lack power development for both players. Through his first 2286 career plate appearances, Hosmer has slugged just 56 homeruns en route to posting a league average-ish .141 Isolated Power, or ISO. And Butler’s work – 123 homeruns and a .154 ISO – aren’t that much better through his eight-year career.

They’re not poor numbers by any stretch of the means, but they certainly aren’t the top of thump that was once forecasted either. To see each players’ top CALs click HERE.

Hosmer’s list is littered with the likes of players like Brandon Belt, Colby Rasmus, Billy Butler, Logan Morrison (three separate times), and Justin Smoak – players that displayed slightly better than average power at this point in their respective MLB careers. Here’s the career ISOs: .141 Hosmer, .157 Smoak, .171 Morrison, .181 Belt, and .191 Rasmus.

Butler’s list isn’t much better. Here is their respective career ISOs: .154 Butler, .166 Wieters, .168 Carp, .172 Morrison, and .183 Freeman.

In fact, not one player on either list has currently developed the type of game-changing, middle-of-the-order thump that was projected for either player. And not one player has slugged 30-HRs in a season. Obviously, Butler and Hosmer have struggled mightily this season, which puts their lack of power further under the microscope.

CAL was, however, a little more favorable towards Hosmer’s future output, so there’s some glimmer of hope.

Just further evidence of CAL’s usefulness.


After serving as a video scout/analyst for Baseball Info Solutions, Joe Werner began writing at his original site, ReleasePoints.com. He’s since transitioned into his current niche, prospect analysis, at ProspectDigest.com. He has been fortunate — and incredibly blessed — to have some of his work published and mentioned by several major media outlets, including: ESPN, Cleveland.com and the Baseball Research Journal. He can be reached at: JosephMWerner@yahoo.com.