Prospect Scouting & Stats — Hitter Spd – Present

As continue our look at scouting grades and stats, let’s now move along to hitter speed, represented by the Spd grade. Although there is also a Future grade, we’re not going to bother with it, as only four of 420 prospects earned a higher Future grade than Present. So all our analysis will be based on the Spd – Present (SP) grades. We’ll start by looking at correlations and grade distribution.

The most obvious stat we would expect to relate to a prospect’s SP is stolen base attempts. While even in the Majors, it’s not going to correlate perfectly, all else being equal, a faster hitter is going to attempt more steals than a slower hitter. So let’s check the correlations between SP and a couple of different stat metrics.

Wow, I would not have guessed that all three metrics would correlate almost identically with SP! These are pretty solid correlations, though not quite the highest we have seen among those I’ve calculated during this series.

The FanGraphs Spd score uses the following components: Stolen Base Percentage, Frequency of Stolen Base Attempts, Percentage of Triples, and Runs Scored Percentage. We know that runs scored percentage is team dependent, so I’m surprised it correlates just as highly as the stolen base metrics.

I calculated both stolen base attempt and stolen base rates to see if there was any difference. You might think that faster players will succeed on their attempts more often, but I don’t think that’s necessarily the case, as stealing bases is as much a skill as it is indicative of a player’s speed. Interestingly, the stolen base attempt rate actually correlated ever-so-slightly worse with SP. It’s such a tiny difference that it’s basically negligible.

While in general I will most likely just look at a prospect’s stolen base attempts in the minors to gauge speed, there is definitely value to the SP grade. If I see a big stolen base total (20+) in the minors, but a mediocre or worse SP grade, I assume those steals are due to good art form, rather than actual speed. In the Majors, that art form might be less successful, or the prospect might be less confident he’ll be able to steal as successfully without above average speed. Since speed isn’t going to wane upon promotion to the Majors (aside from any aging effects), I’d be more confident in a fast guy maintaining a high steals rate than an average or worse speed guy.

Now let’s take a look at the distribution of SP grades.

What’s interesting here is that while it’s generally like a bell curve, it’s not totally, with ups, then down, then ups, following by downs, up, and downs. The most number of players were graded as owning 60 grade speed, which is quite high, and certainly higher than the other tool grades. That shouldn’t be too surprising though as speed is a skill of the young and declines every year, absent some sort of physical changes with the intent of improving speed.

While owning elite speed is better than owning poor speed, the players that do own elite speed are typically weak hitters with little power. We’ll take a look at those top names next time to find out if that’s true of this crop of prospects.