A close look at Rays prospect defense

I am so excited right now.

I just found out Clay Davenport has a website that tracks defense metrics (among many other things) for minor league players. I don’t know all the nuances of how it’s calculated, but his calculations lead to some sort of "fielding runs above average" at a position, averaged over a full season.

Checking a few current major leaguers' profiles speaks to the validity of the system.

Kiermaier's profile shows in an average minor league season he was +21 in CF and +1 in RF score. Davenport's system is tracking Kiermaier at +27 in CF and +6 in RF in an average major league season now.

The site tracked Longoria at +9 runs at the hot corner over an average minor league season, and now +5 runs in the majors. Matt Duffy was +6 runs at SS in the minors and now he’s a +9 major league 3B. Brad Miller was -4 runs at SS in the minors, and is now -3 in the majors. It's not a 1:1 calculation, but it has been a keen approximate for how players have performed at the major league level.

We can use this to get an idea of how well the current Rays prospects are at defending their positions.

This is really good stuff. I haven’t seen this kind of information publicly available before, and it looks like Davenport just started reporting it in 2015, but has full career statistics for most players.

I threw all notable Rays prospects into the table below. The numbers indicate how many runs they have been above or below average on defense over a full minor league season, on average, throughout the prospect's career. Primary and secondary positions were determined by number of games played at the positions.

*Prospects are ordered by primary position played.

All things equal (they’re not), it looks like the best defender in the organization could be Nick Ciuffo at +27 runs in an average full season. Umm, wow. Can someone please teach him how to hit a line drive and draw a walk every once in awhile so we can get that defense behind home plate at the Trop?!

It should be noted that Ciuffo is not actually +27 on the year, but it looks like Davenport is suggesting he would be over a full season (he's actually +15 in 242 PA). This is pretty exciting because the method we are using is averaging the numbers from his whole career, so there's less chance of this being a fluke. The bat is no where close to being even average, but the kid is still only 21 so he has all kinds of time to figure something out there.

Other plus defenders include Gillaspie at 1B, Maile at C (something he's proving at the major league level now), possibly Bauers in RF (!!!), Gotta in RF/CF, Williams in RF, Goetzman in LF, DePaw at C, Justin O’Conner at C, Milone in CF, Heim at C, Rodriguez at C, possibly Law in CF, Moreno in CF, Mastobuoni at 2B, Pujols at SS, De La Calle at C, Melley at 1B, and Cabrera in RF.

Notable poor defenders include Robertson at SS, Shaffer at both 3B and RF, Hager at SS, Beckham at SS, Unroe at 2B, James at C, Toribio at SS, Cronenworth at SS, and Brandon Lowe at 2B.

There’s two things I’d like to note about the lower minor league guys. One is that many of them are still learning how to play their position. The other is that the sample size is still very small with some of them. Put the two together and you may see some volatile swings in metrics.

For example, Kevin Padlo was a great defender in 2015, but is -11 runs at 3B so far in 2016. On a more positive note, Adrian Rondon was -11 runs at SS in 2015 and is now +1 at the position in 2016. We may need to wait for more data on the lower level guys before putting much weight into this statistic.

Either way, it’s more information for us to chew on, and boy is it tasty.