Editor's note: Steve Carter is a former college player turned swing analyst. He has spent the last 4-5 years studying, experimenting and drawing upon his own experiences to better understand what makes professional hitters successful. He has asked us to publish his work under a pseudonym.
Buster Posey is one of the safer bets in the minors to live up to his lofty prospect rating. He certainly has the talent and athleticism to emerge as an average or better big league hitter, but that isn’t to say that Posey’s swing is already maximized. As good as he is right now, he still has room to improve the efficiency of his swing.
Posey’s bat is very close to being big-league ready. He blends bat speed, swing quickness, leverage, and very good plate discipline into one package.
Starting in an open, deep, crouched stance with his feet spread wide, Posey coils his front knee toward his back hip before striding forward to neutral position. This type of timing mechanism allows him to: 1) load his back hip for the eventual rear hip thrust and weight shift 2) maintain his rear hip load as he moves forward and 3) gives his lower body a bit of a running start -- or kick start -- so that he's able to catch up with high-velocity fastballs. His crouch gives him the ability to maintain leverage in his lower half, helping him direct all of his energy and power into the ball.
Upper Body = Matt Holliday?
Posey doesn’t have a large, power-hitter’s frame, but he’s an excellent athlete and his abilities show in his natural and smooth stroke. He keeps his upper body tall and doesn’t hunch over, giving him the ability to reach any pitch in the strike zone. His upper body loading pattern is very similar to that of Matt Holliday. Both start with the bat parallel to the ground, but as they load, they bring the bat down and back with their hands to a vertical position and end up with the knob close to the shoulder level. Having the bat in a vertical position at launch maximizes a hitter’s ability to get and maintain a tight, direct barrel arc through the hitting zone.
While Holliday takes advantage of his Herman Munster like size and uses his bottom hand more than his top hand, Posey utilizes his top hand extremely well and gets his hands flat very quickly.
(Getting your hands flat as you swing optimizes how long the barrel is in the hitting zone, increasing your chances of making solid contact -- this also helps with palm-up extension through the ball.)
Posey is able to get his hands inside the ball well, showing that he can fight off tough, inside pitches and maintain a high line drive rate. He keeps his hands back well, which gives him time to see the ball just about as long as possible. Posey gets the bat into the hitting zone very quickly and is not long to the ball. He also keeps the barrel in the zone for a long time.
Smooth and Disciplined
He loads back with his hands instead of his shoulders -- counter rotating is a common mistake with many hitters who start in an open stance-- and gets to a good launch position on time. There are no forced movements and he is not mechanical. Rarely do you see Posey late, as he has both the bat speed and swing quickness needed to catch up to hard fastballs. Posey sees the ball well and has good plate discipline.
A Swing In Transition
Despite his success in the minors and quick climb to Triple-A, Posey does have a few things to iron out before he realizes his full potential. In watching the video above, you can see a progression of things he’s worked on since entering pro ball (the first swings are at Spring Training, and later swings are with San Jose).
How He Has Adapted
While at Florida St. and at the start of his pro career, Posey was a tiny bit taller in his set-up, and did not have a front knee coil. He would lift his front leg to medium height before striding forward, but did not coil with it. As he's progressed toward the big leagues, Posey has gotten in a bit of a deeper crouch than before and started with more weight on his back leg, visible in his slightly more vertical rear shin. By starting in a deep crouch with his rear leg pre-loaded, he improves his ability to keep his weight centered on his back leg as he strides forward.
Posey generally maintains his rear hip load as he moves forward, but he's a bit of a momentum hitter, as you can see in the video where he was fooled and out in front. Not taking anything away from the pitching he is facing, but if he were to maintain his rear hip load better, he would be able to do more with those pitches than just foul them off or hit weak ground balls.
As Posey gains momentum toward the pitcher after his coil, he occasionally reaches out too far with his front foot, instead of riding his rear leg into foot plant. When his stride gets overly long, it displaces a tiny bit of weight onto his front side. This pulls weight out of his rear hip load and moves it into the middle of his pelvic area. Being very wide and spread out with his feet helps him control his body’s movements, but when he reaches too far forward he loses the ability to fully maintain his rear hip load. Posey's best swings come when he is riding his rear leg all the way to foot plant, and not letting his front leg reach too far forward.
Shifting Too Early
When Posey gets onto his front side prematurely, he becomes too handsy in his swing as he fights to make contact. When he shifts or loses his weight too early, Posey will rush with his hands and go get the ball instead of letting it travel as far as possible. Better upper body resistance or always focusing on riding his rear leg into foot plant would do wonders here. Occasionally his weight can continue drifting forward after foot plant, and while his upper body does a good job of resisting the lower body moving out, it generally loses the battle when he gets onto his front side early -- this is common in many minor league hitters who have not yet mastered their lower body control. When he’s staying back and keeping his stride short, Posey lets the ball get deep in the hitting zone and doesn’t rush to catch up.
Another Thing To Watch For
Something that does concern me is how his front hip appears to be prematurely leaking open. Take a close watch in the later portion of our video. He appears to be trying to pull with his front hip rather than let the front side be opened up by the rear hip thrust. (Note: hip thrust means basically the same as “hip rotation”, except “thrust” is a better description than “rotation”. The rear hip must thrust up and forward during the weight shift, rather than simply spin in an outward arc.)
Adding in a better coil with his front knee would help control his front hip from opening prematurely. Posey’s upper body swing pattern is very well controlled, but as is usually the case with young hitters, his lower body still needs some refinement. With a better coil or a higher leg lift, Posey should be able to maintain his weight being centered on a more consistent basis. This would help him keep his weight back and only come forward once he launches his swing. A few tweaks here and there and Posey should be able to maximize his swing efficiency.
Posey can handle a good fastball right now. What may give him trouble moving forward is good off-speed pitches down and away. Given that his natural stroke is to right center, if Posey could maintain his rear hip load better, he would give himself a better chance to drive those pitches rather than fight them off.
All in all, Posey is a very polished hitter who has an ideal plan at the plate and very well could be the starting catcher for the Giants in 2010. Posey should be a perennial threat to post a .290-300 batting average and rack up his share of doubles. He also has the potential to produce a very strong on-base percentage and garner plenty of walks. He’s not Matt Wieters big, but Posey is strong and has the leverage and bat speed to hit 17-20 home runs a season, with a possible bump up to 25 home runs depending on how he fills out and develops his strength.