Yonder Alonso Has Fully Committed to the New Version of Himself

After being one kind of hitter for the first seven years of his big league career, Yonder Alonso has flipped the script about himself in a big way.

On the verge of entering his age-30 season -- his eighth in the major leagues -- we knew one thing about Oakland Athletics first baseman Yonder Alonso: the man wasn't much of a power hitter.

It's hard to deny that upon taking a look at his first 2,343 plate appearances, especially since it included just 39 home runs and an Isolated Power (ISO) of .118. We got a hint that maybe things would be different in 2017, though. After all, he said that he changed his mind about his plate approach, and it was just a matter of putting it into practice.

That's exactly what he's done through his last 298 plate appearances, evidenced by the 20 homers he's hit and the .287 ISO he's produced.

Based off what we heard back in spring training, it's not surprising how Alonso has made such an about-face with his power production, but he's made sure to basically go to the extreme when it comes to limiting ground balls.

This Looks Awfully Different

Alonso's batted-ball profile doesn't at all resemble anything he's done in the past since becoming a big leaguer. Even though we were warned about an eventual change, it's still pretty crazy to look at when comparing his 2017 performance to what he's done the previous two seasons.

The below table shows how his line-drive rate (LD%), ground-ball rate (GB%), fly-ball rate (FB%), and hard-hit rate (Hard%) have all changed since the 2015 season.


We began this comparison with the 2015 season because that was the high point for his ground-ball rate. There was a slight improvement in that category in 2016, along with his fly-ball rate and hard-hit rate, so maybe we could've expected him to continue moving in that direction this year. However, he put the pedal to the floor with regard to his progress.

But of course, simply hitting more fly balls doesn't mean that such incredible results are bound to follow -- he had to make the most of what he was doing. Which is exactly what he's done.

Since his first full season in 2012, his performance on fly balls hasn't been all that good. Not only was he not hitting many of them, but his single-season career highs in wRC+ (81), wOBA (.282), and hard-hit rate (39.7%) in this situation didn't instill much fear in opposing pitchers. They also all happened in 2012, so it'd been a while since he was anywhere close to being a force upon putting the ball in the air.

In addition to this year's spiked fly-ball rate, he's on pace to smash every number he's produced on fly balls in the past -- off the strength of a 40.2% hard-hit rate, Alonso's wRC+ (256) and wOBA (.546) on fly balls show he's every bit of a different hitter in 2017.

What's also interesting is that he's experienced this power surge by having more success against two of the three pitches he's seen the most over the first half: four-seam fastballs and sinkers. He produced a wRC+ of 100 against four-seamers and a 131 wRC+ against sinkers last year, but those numbers have increased to 218 and 258, respectively, in 2017.

On the Verge of Rare Company

Being part of the fly-ball revolution isn't anything new -- even if he's becoming the poster boy for it. But still, the extreme measures he's gone to make this possible is rather impressive. He's also putting himself into rare company when we look at recent history.

Alonso may have just the fifth-lowest ground-ball rate among qualified hitters this season, but none of them are enjoying the type of campaign he's having, either. His 148 wRC+ and .388 wOBA is easily better than each of the four hitters before him, but it gets more impressive when we look back.

While his ground-ball rate has crept just over 30.0%, it's actually been below that number for virtually all of the last three and a half months. Since the 2010 season, there have only been four hitters (five if we include this year) with at least 200 plate appearances in a season to have a ground-ball rate below 30.0%, a fly-ball rate above 45.0%, and an ISO that eclipsed .250.

This group includes Ryan Schimpf (2016), Chris Carter (2014), Trevor Story (2016), and Brandon Moss (2016), with Joey Gallo also currently on track to accomplish this. If Alonso can get his ground-ball rate back under 30.0% while producing at the same rate, he'll differentiate himself by having the highest wRC+ and wOBA amongst this group by a rather far margin.

Going back even further to 2002, this has only happened on 22 different occasions. And when looking at Alonso's current offensive production, he'd land in the top 10 of this group if he can keep this pace up while driving that ground-ball rate back down to where it'd been for most of the first half.

So, while the complete switch he's made in his approach is already impressive, the success he's experienced with a batted-ball profile as extreme as it currently is also takes things to another level.