The 2014 version of Anthony Rizzo would be great enough for just about any team out there: lots of walks, power, and contact. If you were trying to build him into the model of a superstar, the only knock against him would be that he basically didn’t run, but he’s promptly taken care of that this season. Through the first two months of 2015, he’s also shown another remarkable improvement: he’s cut his strikeout rate by a third while slightly increasing his power output. Take a look at his ISO and K% since he was called up in 2011:

Season K% ISO 2011 30.1% .102 2012 16.8% .178 2013 18.4% .186 2014 18.8% .240 2015 12.4% .249

Rizzo’s 2015 is the equivalent of making a Ferrari go a little faster while using less gas; it’s rare we see that sort of development. Recently, strikeouts have become something of a necessary evil with power hitting, so Rizzo’s current strikeout level is a bit of an exception to that relationship. Over the past 15 years, qualified hitters around his ISO (.250) and K% (12.4) make for some pretty great company: Rafael Palmeiro (2003), Albert Pujols (2002), and Bernie Williams (2000) are just a few of the names that come up.

The early 2000’s was a different era for strikeouts, however, so if we just look at the past five years, we see only four qualified hitters who have posted ISOs higher than .250 with strikeout rates below 13%: Adrian Beltre (2011), Edwin Encarnacion (2013), and Pujols twice (2009 & 2010). Quickly, let’s take a look at where Rizzo fits into that ISO vs. K% connection among qualified hitters in the past five years (2009-2014), with those other four players mapped. Rizzo is the red dot, the other four players the blue dots:

We’re not exactly looking at how great of a relationship this is between these two variables (it’s clear there’s little predictive power in it), more where Rizzo lands on the spectrum: he’s not quite an outlier, but he certainly finds himself on the fringes of the sample. Any further improvement in ISO/K% this year from Rizzo would put him firmly in the conversation with those other four seasons we highlighted, which were all nothing less than incredible.

Knowing the sort of territory Rizzo is currently in, let’s take a look at some of the changes that are behind the improved strikeout rate. First, it’s good to know that Rizzo sees some of the fewest pitches in the strike zone out of all hitters in the majors. Take a look at the 10 qualified hitters with the lowest zone rating, coupled with their tendency to swing at pitches outside of the strike zone (O-Swing%):

Loosely, there are two types of hitters on this list: the free swingers and the scary guys. The guys with an O-Swing% above league average are the guys who chase bad pitches, so pitchers don’t necessarily need to throw them a ton of pitches in the zone. The scary guys are the ones below the line, the ones pitchers avoid because they tend to hit pitches really, really far. Rizzo is one of the latter.

About a month ago, when I checked this list, he was seeing the fewest pitches in the strike zone out of any hitter in the majors. Then Bryce Harper decided this year was going to be his year, and pitchers seem to have taken notice. Still, the fact remains: Rizzo gets thrown more junk than just about anyone in the game.

That junk tends to look a lot like what most great power hitters get: a steady diet of pitches low and away. That isn’t really news or a surprise. Rizzo’s vulnerabilities, however, have always been the breaking ball down and in off the plate and the high fastball. Here’s a map of his whiff rates in his career before this season, courtesy of Brooks Baseball:

The low and inside hole in Rizzo’s swing could be a result of the fact that he stands so famously close to the plate: by giving himself greater coverage in the outer portions of the zone, he also opens himself up to swings and misses on pitches down and in. He also leaves himself prone to getting hit by pitches, as evidenced by his 14 so far this year (the next closest player has 10). Sometimes, when facing a particularly nasty slider from a RHP, there’s the infamous confluence of both whiff and HBP:

But we digress. The idea of the hole in his swing being the result of him standing so close to the plate would have been a good theory to work with previously, because there’s this — his whiff rate map in 2015:

No more hole. Or rather, significantly less of a hole — a whiff rate only slightly higher than the other areas below the strike zone. Looking at where he is in the batter’s box, he’s standing just as close to the plate as last year. That theory is out the window. He’s also improved on pitches up and out of the strike zone, especially on the middle/outer portion of the plate. So what has he done to take that hole out of his swing?

Much of the improvement is simply better plate discipline: he’s now laying off more of those pitches out of the zone, and the ones he is swinging at, he’s hitting at a higher clip. Here are his plate discipline numbers — notice the O-Swing% and O-Contact% improvements:

Season O-Swing% Z-Swing% Swing% O-Contact% Z-Contact% Contact% Zone% 2011 32.90% 64.60% 46.80% 50.00% 81.00% 68.70% 43.80% 2012 35.30% 68.10% 50.50% 63.90% 91.00% 80.90% 46.50% 2013 31.10% 62.00% 44.90% 64.20% 89.40% 79.80% 44.80% 2014 31.40% 59.50% 43.90% 64.40% 89.70% 79.70% 44.50% 2015 27.70% 62.40% 41.70% 70.20% 91.90% 83.30% 40.30%

A career-low in-zone rate (which is one of the lowest rates in the majors) and career-highs in overall contact and laying off bad pitches: the recipe for a low strikeout rate. Rizzo is simply showing a more mature plate approach this year while making better contact on the pitches he is swinging at. That brings up the next question: are there any mechanical adjustments Rizzo is making to better reach the pitches he used to have trouble with?

There very well could be a change in his situational (especially two strike) approach this year. Let’s look at a combined GIF of him from July of 2014 (left) vs. May of 2015 (right):

Lots of things jump out immediately. He’s more upright this year. The bat is quieter, with less tipping (how far forward the bat head is brought during swing loading). Finally, there’s now a toe tap instead of a leg kick. Looking back through a few examples, he was doing this last year on many two strike counts, just not to the level that we see in 2015; perhaps Rizzo is better identifying the situations in which to quiet down, and the ones in which to be aggressive. The leg kick is still around in most situations this year, but when Rizzo goes to his contact-minded approach, he quiets down significantly.

The prospect of a better all-around Rizzo is a scary one for pitchers considering how great he was in 2013 & 2014. He’s added speed to his game almost of out nowhere, and he’s cut down on his strikeouts by a significant margin without losing his ability to hit for extra bases. If this change sticks long term, he’ll put up the sort of seasons we’ll highlight in articles like this ten years from now — the ones that currently are owned by players like Palmeiro, Pujols, and Beltre. Given that he’s still only 25, there’s room for further growth: that’s great news for the Cubs, and terrible news for those who have to face him.