Bryce Harper is about to have his best season. His swing is beginning to take shape. The violence is still there, the head-turning bat speed hasn’t left him, but he now has a much more efficient movement pattern. To understand this process, let’s compare his swings from 2012, 2013, and this year’s spring action.

Before diving into the individual years, I’ll point out what makes Harper a special hitter from a mechanical perspective. He generates incredible bat speed through the most athletic means possible. Yes, his hands move quickly and yes, his lower half is incredibly strong and forceful. What links these components together is the remarkable use of his hips and an impressive sense of internal timing. Harper’s hips don’t have the flexibility some of his peers have, nor the obvious strength of a hitter like Javier Baez. What he does have is the ability to clear his front hip early and then time the rest of his swing to his hip action. Think of all the physical components (hands, hips, legs, etc…) of his swing as instruments. His orchestra of baseball-crushing fury is masterfully conducted by his sense of internal timing.

Here are the three swings side by side. 2012:



As a rookie Harper arrived in the majors channeling his inner adolescent Roy Hobbs. He came into the show with an extremely athletic swing. In this swing we can see some features of his mechanical identity. The first is a deep starting position with his hands. When he loads his hands he doesn’t change the angle of his front elbow. He moves his hands up to about the level of his ears. The other identifying feature of his upper body is how he steepens the angle of his bat as his lower half moves forward. These are movements hardwired into Harper’s mechanical profile like Javier Baez cocking his elbow or Chris Davis bringing his hands down and tight to his body.

His lower body has its own identifying feature as well. Harper can change his stride type from a bigger leg lift to a toe tap when he needs to. What doesn’t change is how he proceeds through the strides. His front foot kicks out well in front of his knee. Compare this to a hitter with a similar sized leg lift: Carlos Gonzalez.

Cargo’s front foot actually comes even with his knee before they both launch forward together. In Harper’s case, at the top of his leg lift his front foot will seemingly reach forward before the rest of the swing goes on.

In 2012 he had some “noise” with his stride. Watch his front foot. He picks it up at a fairly flat angle. Then as he brings the foot back down he really points it down to the ground combined with a slight twist. He lands on a pointed toe but then quickly rotates and drops the heel to flatten out his foot. For his swing to line up he has to lift the foot flat, point it, rotate inwardly, land on his toes, and counter rotate while dropping the heel. Whoa.

On top of a complicated stride, the actions of his front leg are numerous too. He lands on a soft front leg which stays bent for a fairly long time. When he does firm up his front leg, even that is done violently. He locks it up for a split second at contact before softening it again, leading to a visible ripple of energy through his front leg.

The 2012 season was a solid glimpse into the stats Harper could be putting up. He had the foundation to improve his already impressive set of mechanics.

The 2013 season is a tough read for Harper. He tweaked numerous things in his swing, including his stance height and his hand position, and his trademark intensity was tempered late in the season. More important than any of these changes was a series of injuries, starting with a collision into the wall at Dodger Stadium. When he ran into the wall he did so with the left side of his body. Why is this important? Watch his swing and look what happens after his bat reaches maximum extension but before it rests on his shoulders on follow through. Focus on his hips. There is noticeable recoil of his hips. They turn inward as he concludes his swing. Never having seen this movement before, I went back and checked film on around 50 big leaguers and none of them had this type of recoil.

I’m no doctor. But I tried to emulate this hip action in the batting cage and it was very uncomfortable on my back hip. Harper has had this hip recoil in his swing since his days hitting 500-foot bombs at Tropicana Field. The 2013 season was the first time he has had an injury to the left side of his body. When one body part is injured the surrounding areas usually try to compensate. His left hip was already being pushed to the limit thanks to the inward rotation and lack of strength in his knee (thanks to another pesky wall).

All of this is to say his 2013 swing was fighting an uphill battle. Look at the piping on his pants in 2012 vs. 2013 at the point of contact. In 2012 you see the piping running down his leg at an angle as his back knee is actually in front of his back hip; in 2013 the piping is running straight down his leg thanks to his back knee only coming forward directly under his hip. This much change is indicative of some sort of weakness in his lower body.

Much has been talked about with Harper’s back foot coming off the ground during the course of his swing. No issue. Mickey Mantle was doing this long before Harper. The real issue here is how his injuries in 2013 made that movement look exaggerated. In 2012 his back foot is moving forward from the time his hands launch to the time he makes contact. His healthy hip is able to pull the thigh (knee included) forward, leading to the back foot coming off the ground so as to not stop momentum. In 2013 his back foot starts at the same time but his injured hip and knee don’t seem to be allowing him to create that solid forward momentum. Instead of progressing forward his back foot just lifts up from hand launch through contact.

If healthy his knee might have been able to supply some torque, as Harper will rotate his back knee inward before launching forward. This inward rotation of the knee is fine if the hitter can use the momentum created early in the swing to get the knee where it needs to be at contact. Harper has never had a problem with this kind of timing. But in 2013 this inward rotation, and any additional strength he could have gained from it, was diminished. His back knee didn’t inwardly rotate as aggressively; it was actually moving forward much sooner in the actual sequence of his swing. He didn’t have the stability to load the knee as aggressively, nor the strength to explode it through the zone. He had to commit his lower body a fraction of a second earlier to the pitch, tipping the scale more in the pitcher’s favor.

Harper was hampered in 2013, and his swing suffered mechanically. The crazy thing is that his stats improved. Following his injury, he lost some ability to generate extra-base hits, but his natural athleticism and timing allowed him to rack up a respectable amount of hits. This is why I think 2014 could be a monster year for Harper: His health is back to where it should be, and his swing is better than ever.

All the pieces are in place for Harper to come into his own this year. (The BP staff agrees, picking Harper as a slight favorite for the NL MVP Award.) Mechanically, he has never been in a better place. His swing is much smoother and more efficient, and he didn’t sacrifice any violence, torque, moment, or intent in doing so.

Harper has kept his mechanical identity. His hands still start far back and load up while his bat cocks behind him. His front foot still kicks out in front of his knee. These movements have been streamlined. The hands don’t come up quite as high. The front foot doesn’t kick out as far. The actual stride is incredibly improved. His foot lifts off the ground and doesn’t go through any of the superfluous gyrations it did in his previous years. His front leg lands with some bend but firms up much sooner.

Most hitters would be happy to simply clean up their swings, but Harper is not most hitters. He has added a new movement to his swing this year, and I love it. His front hip now moves forward as his front knee rises. This is a great way to start momentum early in the swing. In previous years his hips moved forward but later in the swing (as his front foot came down). It was more of a result of a late burst of energy in the swing. This year his early hip movement helps build that energy. The best hitter in the game has a very similar movement in his swing.

In 2013 Harper’s backside left much to be desired. This year his knee is back to full strength, as he is able to inwardly load on his knee and still have enough momentum (thanks to a healthy hip) to drive his knee forward. His knee is able to get in front of his back hip. His back foot still has its trademark aggression but now the movement is just a tad up into the air, then powering forward. This is marked improvement from his past years.

In 2012 Harper took the league by storm. In 2013 he produced despite injuries. This will be the year that everything clicks.