The Yankees are off to a much better start than many expected. Young players like Aaron Judge and Aaron Hicks have contributed from day one. Veterans like Jacoby Ellsbury and Starlin Castro, whom many had thought were lost causes, are off to hot starts offensively. Perhaps the most notable veteran off to a great start is Chase Headley. After two very disappointing years at the plate for the Yankees, Headley has come out of the gate on fire. Some would chalk this start up to good luck. As of Monday, Headley is hitting .301. He hasn’t finished a season above .250 since his career-year with the Padres in 2012. Clearly there is some truth to this claim, as his BABIP is .361. No player, especially one with the track record of Headley, can sustain a BABIP that high.
However, it is not the high average for Headley that stands out to me. It is his new found power. Here are his career slugging percentages and isolated power, including this season:
| Season | Team | PA | SLG | ISO |
| 2007 | SDN | 21 | .278 | .056 |
| 2008 | SDN | 368 | .420 | .151 |
| 2009 | SDN | 612 | .392 | .131 |
| 2010 | SDN | 674 | .375 | .111 |
| 2011 | SDN | 439 | .399 | .110 |
| 2012 | SDN | 699 | .498 | .212 |
| 2013 | SDN | 600 | .400 | .150 |
| 2014 | SDN/NYA | 531 | .372 | .130 |
| 2015 | NYA | 642 | .369 | .110 |
| 2016 | NYA | 529 | .383 | .133 |
| 2017 | NYA | 81 | .494 | .193 |
Headley is currently slugging almost .500. He has barely touched .400 since 2012. Yes, the sample is extremely small but this sort of power is a far cry from what we have seen from him during his career in pinstripes. Even if Headley were to return to his 2016 form tomorrow, this hot start would be enough to significantly improve his power numbers on the year. His six doubles this season are already one-third of his 2016 total, 18. His WARP so far this season (1.2), is already comparable to his career high as a Yankee (1.6 in 2016).
What’s causing this power surge for Headley? One thing that stands out is his improved plate discipline so far. He has walked almost as much as he has struck out (14 BB, 19 SO). However, he seems to just be swinging less — not laying off balls. If you look at his plate discipline numbers (shown below) you can see that both his Z-Swing and O-Swing rate are down over 10 percent from last year. His Z-Contact rate is actually down slightly from last year. Swinging at fewer pitches certainly explains his elevated walk rate this year (14.4 percent in 2017, 9.6 percent in 2016). However, laying off more pitches in the strike zone and making contact at a very similar rate on those pitches does not explain the increase in power.
| Season | Z_SWING_RT | O_SWING_RT | Z_CONTACT_RT | O_CONTACT_RT |
| 2015 | 0.6139 | 0.2483 | 0.8781 | 0.5652 |
| 2016 | 0.6419 | 0.2548 | 0.8494 | 0.5254 |
| 2017 | 0.5514 | 0.2202 | 0.8137 | 0.6216 |
So is this all just a BABIP driven fluke? Possibly. But there are some other changes that suggest maybe the power is here to stay. Headley is putting the ball in the air a lot more this season. Here are his batted ball numbers from the past three seasons:
| Season | GB/FB | LD% | GB% | FB% |
| 2015 | 1.42 | 26.6 | 43.1 | 30.4 |
| 2016 | 1.38 | 23.8 | 44.4 | 32.0 |
| 2017 | 1.10 | 27.9 | 37.7 | 34.4 |
via Fangraphs
As you can see, he is hitting the ball on the ground less. His ground ball percentage is down and both his line drive and fly ball percentages are up on the season. When we look at his Statcast batted ball data it tells a similar story:
| Season | Events | Avg Launch Angle | Avg Exit Velocity |
| 2015 | 449 | 11.8 ° | 86.6 MPH |
| 2016 | 354 | 11.7 ° | 87.1 MPH |
| 2017 | 62 | 12.9 ° | 87.1 MPH |
via baseballsavant
Although Headley is not hitting the ball any harder this year, his launch angle is up over a degree, after being almost identical the past two seasons. Here is a breakdown of his offensive numbers on batted balls. (A ball hit with a launch angle of 10-25 degrees is a line drive, fly balls are between 25 and 50, and pop ups have a launch angle of greater than 50):
| Season | Number of Events ≥ 10° | AVG ≥ 10° | SLG ≥ 10° | Number of Events < 10° | AVG < 10° | SLG < 10° | % Batted Balls ≥ 10° |
| 2015 | 232 | .409 | .664 | 209 | .249 | .273 | 51.7 |
| 2016 | 181 | .403 | .740 | 162 | .272 | .278 | 51.1 |
| 2017 | 36 | .417 | .861 | 24 | .333 | .333 | 58.1 |
via baseballsavant
This increase in launch angle has likely contributed to his success. When Headley puts the ball in the air he is significantly more productive. Even in his overall poor offensive seasons the last two years, Headley had a lot of success on line drives and fly balls. Headley did not need to get stronger or hit the ball harder in order increase his power. He has simply put the ball in the air at a higher rate this season and benefited from the success he was already having on line drives and fly balls.
Now, I am not claiming that Chase Headley is going to start slugging like Giancarlo Stanton. However, this is a man who did not have an extra base hit in April just one season ago. It does not take much in terms of power to make a major improvement. His on base numbers are certainly due to regress. By no means is Headley a .300 hitter — he is hitting for a very high average on ground balls that should regress towards his averages of the past few seasons. However, his success on batted balls in the air is for real. If he is able to maintain or even improve his current line drive and fly ball rate, Headley can be a decently productive hitter and turn what looked like a bad contract into a steal for the Yankees.
Lead photo: Kim Klement / USA Today Sports