Cardinals: What’s behind Nolan Arenado’s hot start?

Cardinals star Nolan Arenado is putting up insane numbers to start the season. The key to his success at the plate is relatively simple.

Going into this season, Cardinals star Nolan Arenado was determined to get better. Now that he completed a full year of playing in the pitchers’ park that is Busch Stadium III, Arenado is fully acclimated to his surroundings. While manager Oli Marmol and others raved about him, no one really saw Arenado coming out of the gate with a 1.650 OPS.

Now I know what you’re probably thinking. It’s the first week of the season, and the Cardinals have only played four games so far. The starting pitchers Arenado has faced are not even above replacement-level. JT Brubaker, Mitch Keller, Bryse Wilson, and Daniel Lynch all have a combined career WAR of -1.1.

However, a .438/.471/1.188 slash line is off the charts against any pitcher. So what’s the key to Arenado’s success? He’s destroying fastballs.

According to Statcast, Arenado is hitting .500 against fastballs (four-seamers and sinkers). In addition, when he makes contact, the average exit velocity of Arenado’s bat is 99.7 MPH. The result so far? Not only a high batting average, but a wOBA of .834 and a slugging percentage of 1.500.

Against fastballs (particularly the sinker) right now, Arenado is tearing the cover off the ball. Unfortunately, what Arenado is doing right now is not sustainable, and eventually, there will be a regression to the mean.

A quick look at some predictive statistics (xBA, xwOBA, xSLG) in Statcast show that Arenado is getting some luck on the fastballs, as these stats are higher than BA, wOBA, and SLG.. There is also a big drop off in Arenado’s performance when facing breaking balls (sliders, curveballs, etc.). That’s something to keep note of as the season goes on.

That said, it’s better to be lucky than unlucky and having a red-hot Nolan Arenado carrying the Cardinals to wins in April will be huge as the season goes on.