NERD for Baserunning

If you’re a more or less normal, sensitive American male like myself, you were shocked and/or awed by the revelation — courtesy of R.J. Frigging Anderson’s article of last week in re Jay Bruce — that Baseball-Reference is currently in the business of keeping a stat called XBT%, or Extra Base Taken Percentage. What this stat tells all of us normal, sensitive American male-types is the — and I quote — “percentage of times the runner advanced more than one base on a single or more than two bases on a double, when possible.” In other words, the stat seeks to represent the frequency with which a player takes an extra base. Also, in other words: it’s awesome.

And not only that, but B-R also records Stolen Base Opportunities (SBOs) — i.e. “the plate appearances through which a runner was on first or second with the next base open.” I feel no shame in not having formerly realized this — I mean, I’m a pretty important guy with a lot on my figurative plate — but I give thanks and praise now for having discovered it when I did.

In any case, here’s why I bring up all this junk: if one were in the business of attempting to adjudge the aesthetic pleasure provided by certain players, then one would very likely be curious about the baserunning skills of those players. As I, Carson Cistulli, am such a “one,” then it follows logically that I would be interested in such a thing.

Though baserunning is, admittedly, a rather minor part of a player’s overall contribution, it’s also a contribution which is rather easy to isolate. In what follows, I’ve attempted to do just that.

So, what makes an interesting baserunner? Well, I’m sure we could have all sorts of fist fights about that (and might soon at the FanGraphs Live Event). In this case, however, I allowed my enthusiasm to guide me unapologetically.

Much like with pitcher NERD, I utilized z-scores (i.e. standard deviations from the mean) to arrive at baserunning NERD (rNERD). In this case, I used a sample of players who’ve recorded at least 100 plate appearances. For each player, I found the sum of three different z-scores: XBT%, SBO% (that is, stolen base attempts as a percentage of opportunities), and stolen base success rate (SB%).

From there, all I did was cap the lowest possible SB% z-score at -1.1 (to mirror the highest z-score) and then add a constant (in this case, 4.91) to put all the scores on a 0-10 scale.

Using this method, here are the Top 25 baserunners (from a sample of 350 qualified players):

I like this list, because there are very few surprises. I mean, Michael Bourn, B.J. Upton, Rajai Davis: we know those are fast guys. The pleasure from such an exercise, however, frequently comes from the players who surprise us. In this case, Kyle Blanks has to be that guy. Surprisingly, Blanks is among the league leaders in taking the extra base. Why that is exactly — maybe batting ahead of lefties, or something? — is unclear, but it makes for something to think about when Blanks makes his retun to the field in August sometime.

As for the 25 laggards, here they are:

I don’t know that there are too many surprises here. Mostly, it’s a list of first basemen and catchers, which is probably to be expected. The presence of Mitch Maier might be of some concern to Royal fans — although, truth be told, they have enough on their plates. Nick Swisher, like Maier, has been seen roaming centerfield more recently than not. He’s never been a speed demon, but it’s surprising to see him on this list.

If you’re interested in seeing the full spreadsheet of 350 baserunners, it’s available just by clicking here.