What’s driving Didi Gregorius’ success with the Yankees?

The (very) early stages of the Yankees’ season could be going better, to say the least. Sluggers aren’t hitting, injuries are piling up and there have already been a number of bad losses. Given last year’s finish and the offseason splash made by Brian Cashman, this slow start has been the most unpleasant of surprises.

Of course, Didi Gregorius’ red-hot start does not fall into this category.

Gregorius has been on a tear since Opening Day, as he continues to blossom into one of the best shortstops in baseball. Every season since his arrival to the Bronx in 2015, Gregorius has vastly improved some part of his game to become a more complete player. His power numbers skyrocketed from 2015 to 2016, and continued to improve last season. Now, we are seeing an increase in plate discipline, which has contributed to one of the hottest starts in the league, as Gregorius finished the weekend with a league-high 1.430 OPS.

Last year, we talked about how Gregorius could follow Robinson Cano’s path to stardom if he chased less pitches out of the zone. We could be seeing the start of that trend right now, as Gregorius has been chasing less pitches, striking out less and doing more damage:

The sample size is small, put in almost 50 plate appearances, Gregorius has shown a much-improved ability to work the count and lay off of pitches out of the zone, especially fastballs. Here is his whiff percentages by pitch in 2017, then compared to this season:

Thanks to his improved plate discipline, Gregorius has already walked a league-high nine times through the first 10 games of the season. Some of it could have to do with how he is swinging the bat right now (and maybe how some other Yankees aren’t). If Gregorius refuses to bail pitchers out and makes them throw strikes, he will be in for a huge year.

One of the most important aspects of Gregorius’ early-season surge has been his ability to cover the strike zone. We’ve seen him turn on pitches on the inner half and deposit them in the right field seats, or loop a two-strike pitch on the outer half into left field for a two-run single, as showcased in his amazing 8-RBI day last Tuesday.

As our own Kento Mizuno pointed out over the offseason, part of what makes Gregorius great is his aggressive approach at the plate, which has not been lost as he becomes more selective. We saw Gregorius jump on a first-pitch fastball from Chris Archer last week for his first home run of the season, while also climbing the ladder on a high two-strike fastball for his second dinger. The aggressiveness is still there, but Gregorius has become a smarter hitter in choosing when to be aggressive, which should be a scary combination for opposing pitchers.

Since arriving in the Bronx, Gregorius has worked to learn his strengths and improve upon them. The power arrived first, and now the plate discipline is starting to follow suit. As Gregorius continues to evolve into a star, it would probably be a good idea for Brian Cashman to extend the man, preferably yesterday.