Projecting Javier Baez and Quantifying His Improvements

Taking full advantage of the September roster expansion, the Chicago Cubs called up 22-year-old infielder Javier Baez to help fortify the team’s middle-infield situation. This isn’t Baez’s first taste of the big leagues. In fact, he doesn’t even qualify as a rookie anymore. As you probably recall, he spent the final two months of 2014 season in the majors, where he turned in a historically bad performance as the team’s second baseman.

Just how bad was it? Baez hit a pitcher-esque .169/.227/.324 in 52 games with the Cubs last year. His on-base percentage was the lowest of any hitter who recorded at least 200 plate appearances. Most alarming of all was his 42% strikeout rate, which made him the only player in the game’s history to have a strikeout rate above 40% in more than 200 plate appearances.

After his strikeout woes continued into this year’s spring training, the Cubs had Baez open the year in Triple-A, and kept him there until last week. Baez hit pretty well following his demotion. In 70 games, he hit .324/.385/.527 — which was good enough for a 144 wRC+. That’s markedly better than his 108 wRC+ at the same level last year.

The improvement had much to do with Baez’s strikeout rate, which dropped from 30% to 24%, but the improvements didn’t stop there. Here’s a comparison between Baez’s 2014 and 2015 seasons, using stats that have been regressed for sample size and centered to league average.

Outside of the power department, Baez has improved in nearly every aspect of his game. His strikeout rate is the most notable improvement, but he also managed to hit for a higher BABIP and stole bases more frequently. At the same time, though, he’s also a year older than last season, so some amount of improvement was anticipated. The expectations for a 22-year-old are naturally higher than they are for a 21-year-old.

Still, even with his being a year older, KATOH prefers this year’s version of Baez to the Baez from last August — the time of his first call-up. Baez’s 2015 numbers earned him a forecast of 11.4 WAR through age 28, up from last year’s mark of 7.6.

One could also observe Baez’s improvement by comparing his Mahalanobis comps between this year and last. Last year’s list reads like a who’s who of failed swing-for-the-fences prospects, and Baez followed a similar trajectory in his rookie campaign. Baez was essentially a Brandon Wood reincarnate in his first go-around in Chicago.

But this year’s list of comps features many more successful players, from Starling Marte to Ray Durham to Curtis Granderson. Like Baez, most of these hitters didn’t make a ton of contact, but also didn’t strike out alarmingly often. They relied on a combination of modest power and speed to put together very good offensive careers.

As Kiley McDaniel noted in last week’s chat, the Cubs summoned Baez to the big leagues somewhat prematurely on purpose to give him a sense of what he needed to work on. Their hope was that he’d take notice of the holes in his swing, and refine his approach to patch them up. Based on his minor-league numbers, it seems he’s made some progress in this regard. His strikeout rate is still higher than you’d like to see, but it’s trending in the right direction. Even more encouragingly, he’s made these improvements without giving up much of the power output that’s made scouts drool over him since he was in high school. Perhaps that means he’ll do a little less of what’s depicted in the first 10 clips in the following GIF, which Owen Watson crafted using video form Baez’s rookie campaign.

Baez appears to be a much better player than he was this time last year, but he’s still very much a work in progress. Although he hacked six percentage points off of his Triple-A strikeout rate between this year and last, he still whiffed 24% of the time in the minors this year, and is projected for something like a 30% strikeout rate in the big leagues. To make matters worse, he accumulates many of those strikeouts by swinging through pitches in the strike zone — a trait that’s common among hitters who have trouble transitioning to the big leagues.

But there’s still plenty to like about Baez’s game. His power is obviously pretty special, he runs well, and is capable of playing the middle of the infield. And perhaps most importantly, he still has age on his side. Although it feels like Baez is teetering on the rim of the failed prospect bin, he’s still just 22. He’s still three months younger than Maikel Franco, and more than a year younger than both Stephen Piscotty and Enrique Hernandez.

Baez very well may go the route of Brandon Wood or Roberto Mejia. That’s certainly not a rare trajectory for players who have the type of swing-and-miss that Baez does. But it’s much too soon to write him off completely, especially given the improvements he made in his second tour of duty at Triple-A. As was the case a year ago, he’s still very much a boom-or-bust prospect, but the likelihood the Cubs will get to enjoy the boom appear to be growing.