The Other Fifteen

UPDATE: Please to disregard this for now. I've discovered an issue with the IDs in the zone rating database. I'm working on fixing the issue, but until then, this is fraught with issues. My sincerest apologies for the error.

Tango’s Fan Scouting Report tells us something that we can’t tell from the stats alone – what physical tools and skills a player has. But does that tell us anything meaningful? I hooked up the Fan Scouting Report to a database of STATS, Inc. zone rating. (Shamefully, I eliminated all players with fewer than 30 in zone chances.)

I want to note right off the bat that I'm puttering here, just poking the data with a stick. Do not take this as gospel.

Here's a set of scatterplots between each of the individual tools assessed and zone rating:

I’ll also present the correlations – the dotted lines, if you were wondering – as a table:

Arm strength doesn’t seem to correlate well with zone rating – in fact it has the lowest correlation of any of the tools - which surprised me at first. It doesn’t make sense that having a better arm doesn’t make you a better shortstop. But before you go throwing out the analysis as piece of lunacy, give me a second.

In the center is a histogram of each graph. We’ll go ahead and zoom in for a detail. First, overall (average of all tools):

It tilts just a shade to the right, but for our sample it seems to do a pretty good job of fitting to a standard “bell curve” shape. Now, look at the histogram for arm strength:

See how it bunches together? (Unfortunately, R takes the number of groups in a histogram as a suggestion rather than as a hard-and-fast rule, or the graphs would be a little easier to compare.)

If we were to look at how well all baseball players did defensively at shortstop, we’d likely find that arm strength matters a great deal. But looking at players selected to play shortstop, it’s a different story; anyone who doesn’t have the arm for the position has been weeded out, and knowing a player’s arm strength gives us little additional information.

Of course, we’re barely scratching the surface with this. More reading is available here and here, for starters.

Labels: Defense