Dellin Betances' command holds key to his success

Dellin Betances came into this season with high expectations.

The hard-throwing 6-foot-8 right-hander was expected to combine with closer Aroldis Chapman to create a duo at the back end of the New York Yankees' bullpen that would shut down opponents at the end of games.

Those expectations have not become reality yet, however. Betances came out of the gates fast this season, only allowing one earned run through the first two and a half months of the season.

He performed well in Aroldis Chapman's absence when the Cuban flamethrower went on the disabled list with a shoulder injury. However, since Chapman has returned from his stint on the disabled list, Betances has encountered some uncharacteristic struggles, allowing a total of nine earned runs in 6 2/3 innings since Chapman came back on June 18.

In taking a look at the numbers, the root of Betances' issues seem to start with his command. For his career, Betances has a 40.0% strikeout rate and an 11.1% walk rate, according to FanGraphs.

This season has seen those numbers shift. Betances has seen his monthly strikeout rate this season decrease from 50% in May to 36.6% in the month of June. His walk rate has gone the opposite direction, increasing from 15.6% in April to 21.9% in June. So far in July, Betances has walked 47.1% of the batters he has faced, albeit in a small sample size.

To further understand why Betances has struggled to locate his pitches over the last month, the Pitchf/x tool from Brooks Baseball can serve as a useful resource. Since June, the horizontal release point on the two types of pitches Betances throws- a fourseam fastball and a curveball-has changed by .11 feet and .17 feet, respectively, on average.

As a result of the changes in release point, Betances' horizontal movement has been affected, more so with regards to his fastball than the curve. Betances' fourseam fastball averaged a horizontal movement of 0.79 inches in April, and 1.93 inches in May. In June, his fastball had a horizontal movement of 2.28 inches, and to begin the month of July, it is at 2.04 inches.

Betances' command issues have directly translated to more walks, and harder contact. Since Chapman's return, Betances has walked 12 batters in 6 2/3 innings. Batters are also hitting balls a lot harder off him.

Against Betances, the average hard-hit rate for batters has jumped from 7.1% in May to 33.3% in June and currently sits at 50.0% for July. Betances' soft-hit rate has decreased from 42.9% in May to 26.7% in June. In July so far, Betances has not allowed a soft hit. According to FanGraphs, quality of hits are determined by the hang time, trajectory, and landing spot of batted balls.

Besides the quality of contact Betances is allowing, the type of contact is also changing. Betances' groundball-rate and flyball-rate are moving inversely. Betances' groundball-rate was 64.3% in May, but has gone down to 40% in June and 50% in July. Meanwhile his flyball-rate continues to rise, from 21.4% and 26.7% in May and June, respectively, to where it stands now in the month of July, at 50%. This means that batters are squaring up Betances' pitches more frequently and getting them out of the infield, where more outs can be made.

It should be noted that these numbers are a small sample size, particularly with regards to the month of July. However, since Chapman's return, Betances has been trending in the wrong direction than he would like.

With the Yankees ceding first place in the AL East to the Boston Red Sox recently and their bullpen scuffling, they will need Betances to pick himself back up and fix his command issues in order to solidify the back end of the bullpen.