Nolan Arenado is getting better

About two months ago, Purple Row’s Ryan Freemyer published an article titled “Nolan Arenado is already great, but he might be getting even better.” Since then, Arenado has been making a convincing case against “might.”

Arenado already improved at the plate from 2013 to 2015. He went from a below average hitter in 2013 to the league leader in home runs in 2015. But he still had a major flaw in his game. He swung at everything and resisted taking walks. He had the 10th highest chase rate in baseball at 38.5 percent, which led to a poor 5.1 percent walk rate, and an on base percentage that was roughly league average before accounting for Coors Field inflation. His walk rate was the only thing standing in between stardom and superstardom.

We’re almost halfway through the 2016 season, and Arenado has taken that one flaw in his game and dramatically improved upon it. Arenado has more than doubled his walk rate from his first three seasons. From 2013 to 2015, Arenado walked in 4.5, 5.4, and 5.1 percent of his plate appearances. So far this season, he’s walked 10.4 percent of the time. If that weren’t enough, he’s also decided to strike out less this season. In this regard, Arenado improved upon something that he was already good at. His 10.4 percent strikeout rate amounts to a one-to-one strikeout to walk ratio.

This chart show what he has done, but it’s perhaps more significant to think about how he’s done it. The answer is not complicated: he’s swinging less. Arenado is swinging at fewer pitches in general; he’s swinging at fewer pitches in the zone; he’s also swinging at fewer pitches outside of the zone. Notably, Arenado is also making more contact than he has in the past, though this change is less dramatic because that was a part of his game in which he already excelled.

Arenado might be taking a cue from Charlie Blackmon. From 2014 to 2015, Blackmon made a conscious effort to swing at fewer pitches. By doing so, his walk rate jumped two percentage points and his on base percentage increased from .335 in 2014 to .347 in 2015. Arenado’s improvements are more pronounced. The reason why might simply be that better baseball players are also better at improving, which is a slippery claim without supporting evidence, but might be true.

To see the relationship between Arenado’s swing and walk rate, the chart below displays both rates in rolling 15 game averages from 2013 to 2016. It’s not self-evident that swinging less leads to more walks because, for a lot of hitters, it’s not dangerous to stay in the zone. Pitchers have to be careful with Arenado. Additionally, Arenado’s 2016 improvements are sticking more so than they have in the past. Whatever approach he’s taking at the plate right now, he shouldn’t change it.

Courtesy of FanGraphs

Finally, let’s return to the relationship between Arenado’s approach at the plate and his productivity on offense. Arenado’s wRC+, which is a park adjusted measure used to show how much better a hitter has been compared to league average, has increased every year of his career. OBP is a critical component of the metric, which is what caused a lot of people to wonder how Arenado’s 2015 wRC+ could be relatively low despite his home run totals and slugging percentage. His OBP was just above league average while playing half of his games at a ballpark that inflates it. It’s no surprise that Arenado’s 2016 leap regarding his walk rate is accompanied by a rise in offensive productivity in general, despite the fact that his batting average has gone unchanged and his on base percentage has seen a significant but un-dramatic rise.

The season is about 40 percent complete, and Arenado has played in 64 of the Rockies’ 65 games. In that time, he’s has taken the one flaw in his game and improved upon it. Not only is Arenado getting better, but according to Baseball Prospectus’ wins above replacement player (WARP), he’s been the best position player in baseball so far in 2016. He’s been worth 4.2 wins compared to Mike Trout’s 3.6, who is in second place. A lot of that has to do with defense, and this can certainly change by the end of the year. Nevertheless, Arenado’s standing atop this ranking wouldn’t be the case if it weren’t for the improvements he’s made.