Aviles – SittingStill.net’s Kelly O’Connor

When the Red Sox traded Jed Lowrie to the Astros, it sent a clear signal that the team believed Mike Aviles could be a serviceable shortstop in the interim — serviceable enough to give up on a young player who had produced, but struggled with injuries.

There was reason to believe that Aviles was up to to the task. He finished fourth in Rookie of the Year award voting back in 2008 when he hit .325 as a 27-year-old and cranked 41 extra-base hits. Unfortunately, he collapsed the year after and spent much of the season sidelined after elbow surgery. He returned with a bang in 2010, hitting .304 as he returned to full-time duty. However, last year, he collapsed yet again and was sent to the minor leagues before joining the Red Sox in a deadline trade and hitting .317 down the stretch.

For all intents and purposes, coming into the 2012 season, Aviles was a .300 hitter. He hit over .300 in two (mostly) full-time seasons and showed enough in an audition with the Red Sox that the possibility of him maintaining a solid average with some pop could reasonably be expected. Indeed, Aviles sported a .279/.306/.494 line through May 21 — numbers down from the end of April but still solid. However, since then, he’s fallen off a cliff, and it might as well be a literal one.

From May 22 until the All-Star Break, Aviles has hit .239/.258/.316 in 164 plate appearances. There are several other players who are having just as bad stretches — in fact, Aviles’ .239 batting average is “only” the 26th worst in baseball over that time span. However, many of the names on the list are either bit players pressed into additional playing time, are in slumps that won’t last, or offer other types of value behind batting average, such as on-base percentage (Adam Dunn has a .324 OBP despite a .174 batting average in this time span) or power (Jay Bruce is slugging .450 despite hitting .228). Aviles’ whole value to his game is batting average, so when that’s not going well, he’s a huge liability.

If Aviles wants to get back to being worthy enough to start for the Red Sox, he simply has to stop swinging early and often. I can’t count the amount of times he’s swung at a pitch early in the count he had absolutely no business swinging at. It’s one thing to swing at pitches early and often if you can do something with them — quite another to swing at a clear waste pitch that he chases and hacks into the ground or pops up. And pitchers know it. Let’s take a look at some heat maps.

Heat maps (ESPN/TruMedia) showing the location of pitches to Aviles, his swing frequency and contact rate from 4/8/12 – 5/21/12.

Let’s explore what we can learn about the above heat maps that caused him to to have an OPS of .800 for the season at the end of May 21. As you can see, pitchers attacked him mostly on a horizontal plane, mostly placing their pitches middle away. Aviles was more than willing to offer at these pitches, but he preferred to go after the inside pitches, especially higher up in the zone. That plan worked great for him, as he made contact on much of his inside pitches, and of the ones he chose to go after that were on the outer half of the plate, he enjoyed success in that area as well.

So what changed?

Heat maps (ESPN/TruMedia) showing the location of pitches to Aviles, his swing frequency and contact rate from 5/22/12 – 7/8/12.

Pitches shifted more from a horizontal plane to vertical, which is more difficult for a batter to adjust to as they have to change their eye level. In addition, pitchers moved dramatically low and outside, with a significant chunk of their target being outside of the strike zone. Rather than lay off these pitches, Aviles didn’t change his choices on where to swing. Unlike earlier in the year, that hasn’t paid off. He’s still enjoying strong contact rates high and inside, and also middle-in. But suddenly he had much less success in the low-and-outside part of the strike zone, and was pretty much hopeless the further lower and outside the pitches went. And remember, pitchers started throwing low and outside a lot more often.

Let’s look at how Aviles’ batting average has changed as a result:

A heatmap (ESPN/TruMedia) of Mike Aviles’ batting average in a specific date range.

The results here are as expected — Aviles did not do well hitting balls low and away, so pitchers started attacking him more and he still hasn’t done well. This is a clear case of pitchers adjusting to Aviles, but Aviles (refusing?) not to adjust back. What’s interesting here, though, is how he’s suddenly gone cold in the upper right zone. That might explain why, statistically, Aviles is actually unlucky over the course of the year despite his ill-advised attempts to keep going after the low-and-away pitch.

One of my favorite statistics is xBABIP — expected BABIP. Essentially, by plugging in certain numbers into a formula, you end up with xBABIP that tells you whether a batter is over- or underperforming relative to how many balls are falling in for hits. Note that xBABIP is not batting average — it’s showing a batting average on balls in play. For example, if someone has a .250 BABIP, it means only a quarter of hits he makes contact with are falling for hits. If that player’s xBABIP is .300, it means he’s unlucky, and he should have had a .300 BABIP instead. Thus, moving forward, you can expect his game to improve even without making adjustments. Most players hover around .300, but it can be affected by the opposing team’s defense, a player’s talent level changing and pure, dumb luck. In addition, speedy hitters have higher BABIPs as they can beat out infield hits, and line-drive hitters hit for higher BABIPs than groundballers, who hit higher BABIPs than flyballers.

Aviles’ BABIP on the year is .278, but his xBABIP is .295. That would be his best mark in the major leagues — when he hit .325 as a rookie, his xBABIP was .292. A lot of this is due to Aviles posting his best line-drive rate to date at 20.9 percent, with most of that increase being taken out of his fly balls. Interestingly enough, he’s actually hitting more fly balls during this down period, checking in at a 22.73 rate since May 22, 19.33 percent before that. He’s also seeing a bit more of a tick in grounders, but I wonder if his xBABIP is misleading. This is completely anecdotal but I wonder if the uptick there has to do with more soft liners and grounders being hit as he chases pitches down and out of the zone. A liner is awesome when it’s hit hard, but not when it’s a routine out hit to first.

Is this just an extremely prolonged slump? Aviles has a reputation as the type of player that’s scorching hot then ice-cold. I’m going to venture a guess and say no. Looking at the heat maps of Aviles’ prior years, it’s clear to me pitchers are pitching him far more aggressively in years past, and the switch to a vertical plane and throwing balls purposely out of the zone to get him to chase have manifested themselves much more in 2012. If Aviles wants to keep holding down a starting job, he’s going to have to change his approach. And frankly, if I was Ben Cherington, I would be looking for a new shortstop.