Jackie Bradley has been one of the few bright spots for the Red Sox defense this season. Photo courtesy of Kelly O’Connor.

For starters, let’s be clear: the 2014 Red Sox have not played good defense. Not by any stretch. Right now, this is the 26th ranked team in the league in terms of Ultimate Zone rating, with a mark of -9.2, after a 2013 in which they ranked 10th with a 21.6 mark in the same category.

Fire Brand’s Jack Keller took a look at some of the causes for the Red Sox struggles – how changes in the roster have had a factor and how the team can improve going forward. For this column, however, I want to take a look at some of the underlying causes of the poor performance by digging into the statistics.

Among the many great resources Fangraphs provides, one of my personal favorites is the Inside Edge fielding data. Essentially, Inside Edge grades each defensive play for a team based on the likelihood of producing an out. The scale is as follows:

• Impossible (0%)
• Remote (1-10%)
• Unlikely (10-40%)
• About Even (40-60%)
• Likely (60-90%)
• Almost Certain/Certain (90-100%)

It’s an imperfect system, of course, because of its reliance on the subjective judgment of the scout in question, but nevertheless, I find it provides some very interesting insight into what transpires when the ball is put into play.

So the Red Sox rank near the bottom of the league in most fielding metrics, but how do they stack up by Inside Edge’s criteria?

• Almost Certain/Certain (90-100%)

We’ll start with the simplest plays in the game: those Inside Edge labels as “Certain,” with a likelihood of 90-100%. The 2013 squad ranked ninth in this regard, with a solid 98.2% success rate on these plays. This year, that number has regressed down to 97.8%; a seemingly insignificant change, to be sure, but enough to drop them down to fifteenth in the league, just between (gulp) the Marlins and the Mets.

There are few standouts in this regard on the Red Sox roster, but the culprits are who you might expect:

Mike Napoli (95% in 191.0 innings)
Xander Bogaerts (93.9% in 217.2 innings),
Grady Sizemore (92.9% in 65 innings in center)
Jonathan Herrera (85.7% in 55.2 innings at third)

As Jack mentioned in his column this weekend, Sizemore has shown sizeable (no pun intended) rust in his first action in centerfield after a two-year absence, so I would expect him to improve in this regard. However, he’s also been perfect in 74.2 left field innings (only three qualifying opportunities, but still), and with Jackie Bradley developing a stranglehold on the centerfield gig, Grady’s centerfield performance may not matter too much going forward.

Xander Bogaerts has shown his age in the field so far this year. Photo courtesy of Kelly O’Connor.

Bogaerts’ 93.9% isn’t pretty either, but we expected this from him, at least starting out. He’s 21 years old, and his defense is not nearly as polished as his sublime approach at the plate. His miscues have garnered some unfortunate attention, and we may have to deal with them for a little while longer, but I expect he’ll gradually get a better grasp on it.

On the brighter side here, Jackie Bradley Jr. has been perfect in this regard so far, with the third most chances on the roster (23 between center and right field) behind Dustin Pedroia (42, also perfect) and Bogaerts (33).

Strong performance on easy plays isn’t necessarily a great indicator of good defense, however; the Phillies finished with the fifth-best mark in 2013 on Certain plays at 98.5%, and they were the second-worst team in baseball in UZR, with an eye-gougingly bad -65.9. So let’s continue.

• Likely (60-90%)

The 2013 Red Sox were the best team in baseball last season on plays marked as “Likely” by Inside Edge’s scouts, with a lofty 88.2% success rate that bested the second-place Padres by 0.7%. This year that number has plummeted to 78.3%, ranking 21st.

This, I suspect, is the biggest culprit of the Red Sox defensive struggles thus far. It’s not the largest change from 2013 – that belongs to the “Unlikely” category – but a higher frequency of these opportunities means more failed outs, and that’s without mentioning these are plays you can still say SHOULD be completed.

Losing Stephen Drew, an above-average-if-not-spectacular defender who one would expect to excel in such an area, hurts here. And indeed, Drew’s 2013 mark of 84% in this category (14th among shortstops with at least 500 innings in the field) easily outpaces Bogaerts’ current 66.7, which comes on the most opportunities (6) of anybody on the roster.

So, too, does losing Jose Iglesias, who was a 90% fielder on “Likely” plays last season, fifth in the league among shortstops with at least 500 innings played in the field.

• About Even (40-60%)

As if to illustrate the futility of making too many conclusions based on this kind of sample size, the 2014 Red Sox have actually been BETTER than last year’s roster on “About Even” plays, with a 58.8% mark as opposed to last year’s 52.5%. Daniel Nava is also currently a 75% fielder in this category, where Shane Victorino was a 62.5% last season.

(In another quirk, Nava has half as many opportunities in this range (4) as Victorino did last year (8) in 889 fewer innings. Woof.)

Let’s continue.

• Unlikely (10-40%)
• Remote (1-10%)

Among “Unlikely” plays, this year’s Red Sox have converted only 15.4% of their 13 chances thus far, 25th in baseball. Rankings-wise, it’s not a huge divergence from last season (they were 20th last season), but it’s an almost 14 percent drop from 2013’s 29.3%.

Dustin Pedroia has the team lead in “Unlikely” plays, because of course he does. Photo courtesy of Kelly O’Connor.

Among “Remote” plays, the Red Sox have, interestingly, faced the third-most opportunities in baseball this season, and have put away a cool 6.1% of them, tenth in the league. These outs have all been recorded by Dustin Pedroia and Jonathan Herrera, which half makes sense to me.

• Impossible (0%)

Nobody has made an “Impossible” play in the league this season, and nobody did it all of last year. I don’t think this is the issue.

So what have we learned? Well, small sample size disclaimers aside, it’s the easy plays that have deserted the Red Sox thus far in 2014. A 0.4% drop in “Certain” plays and a 9.9% drop in “Likely” plays has done a fair bit of damage. This is a team that lost great defenders in Jacoby Ellsbury, Stephen Drew, and Jose Iglesias, however, as well as
missing Shane Victorino due to injury, so this kind of thing isn’t all that shocking.

Can they turn it around? I think they can. Victorino’s return will play a tremendous role, and Jackie Bradley – now presumably entrenched in the starting lineup – has made centerfield his plaything. Development from Xander Bogaerts will be important, of course, and Will Middlebrooks needs to be a sizeable improvement over Herrera (which Inside Edge says he should be), but there’s plenty of reason to think this Red Sox team will end the season as at least an average defensive team, if not quite at the heights of 2013.