Without knowing it, Chicago Cubs rookie slugger Javier Baez pays homage to Isaac Newton's Third Law of Motion with each swing. He takes big giant cuts and hits big giant homers. The problem is, the equal and opposite reactions to the mechanics that generate all that power render the other parts of his swing wildly unstable.
In Baez's case, it's his massive "hammer." A player's hammer position is how he loads his hands at the start of his swing, and as with any athletic movement—punching, kicking, throwing—you must go backward to create energy going forward. (For this case study, we are going to ignore Baez's lower half.) The hand load is intended to create bat whip, like a twisted towel used to crack unsuspecting freshmen in high school locker rooms, which in turn generates bat speed. Baez's bat whip generates a stupid amount of power, which is why he can belt 400-foot homers like this.
That said, take a look at the image above. Baez's hammer is so pronounced that his barrel is almost parallel to the ground on foot strike. This is where his swing takes a very long and complicated adventure.
Because of Newton, we know his bat head is going to want to respond by aggressively shooting back to where it came: down. Often this energy will be too great for Baez to control, and his barrel will drop below his hands during its natural swing path forward, forcing his hands to correct themselves, by rolling to get back into the zone. A rolling bat head creates topspin, which causes the ball to sink and dive, instead of backspin, which causes the ball to carry.
The problems compound when Baez, in a feeble attempt to harness all this energy, straightens his lead arm too early. Not only does this encourage the rolly bat head, but it also slows down the barrel and cuts off the swing, limiting extension. Ending extension early is like punching someone with fully extended arms instead of continuing "through" your target while your arms are still creating velocity. Extension also increases backspin.
The extreme hammer also puts Baez's elbow high above his head. Hitting coaches talk a lot about slotting. The slot is where the top-hand elbow is right before, during, and slightly after contact, shown in the slightly turned "L" in this Wil Myers picture; a consistent slot is crucial in adjusting bat head placement during the swing. Baez's elbow has to travel far before it reaches the slot, which means that slotting smoothly is nearly impossible. This further exacerbates Baez's issues with bat head control. A hard and inconsistent slot hurts his ability to command his hands on approach to the ball.
Baez pushes the knob and then the bat head away from the zone, causing a long swing, which in turn forces his lead arm to straighten before an optimal contact point. (This is often called casting.) Hitting a baseball with a prematurely stiff lead arm is like trying to drive a car with a jammed steering wheel.
As you can see below, Baez's lead arm is straight before contact, while Derek Jeter and David Ortiz's are still bent and in control of the bat. This allows the two AL East rivals to both hit through the ball (extension) and allows them to direct the bat head with precision.
Furthermore, once Baez's barrel catches up to his hands, his bat begins the natural deceleration of the follow-through. When both arms straighten in the follow-through, the wrists begin to roll, completing the deceleration process. Admittedly, this is less a problem for Baez, simply because he creates so much bat speed that having optimal velocity on ball strike is not a real concern for him. But this is still an inefficiency, since he is making sacrifices to create all that power only to disperse it before he even has a chance to make contact.
Because of Baez's body type (at 6-foot-0, 190 pounds, he's no Prince Fielder), the amount of energy transferred to his hands makes it hard for him to "decide" when to swing—to stay behind off-speed pitches or to dope out pitch type and location. The barrel is almost in control instead of Baez. His load-up makes it impossible for him to get consistent contact, let alone with a flat barrel.
So what we have, in Baez's swing, is a tradeoff at the extremes of human kinetics. In exchange for all that insane bat speed, he has given up control of the bat head through the swing plane. There's a reason his strikeout rate is hovering over 40 percent.
(One thing we don't know is how much of this is a matter of approach. Is the energy he's creating in his hand load so violent it's making it impossible for him to stop himself even if he recognizes pitch type, break, and location ? Or is he literally just deciding to swing at whatever before the pitch is thrown?)
All this said, Baez's month-to-month splits at each level are encouraging. He often started slow, then adjusted, improving each month at each level. Mechanically speaking, a smooth rise in statistical success is more inclined to be from a new comfort level and/or approach than a swing adjustment.
There have been a lot of comparisons of Baez's swing to Gary Sheffield's, but I don't think that makes much sense. Sheffield was a superfreak (he went 31-for-62 with 15 home runs his senior year of high school), using his bat wiggle as more of a timing mechanism and a way to actually slow down his hands than to generate power—it was a way to create rhythm and keep his hands back from jumping at the ball before it reached the hitting plane.
In reality, the man who hit the second hardest ball I've ever seen in person—off Kyle Farnsworth, naturally—had a hammer that was far less pronounced. (In the YouTube link above and in this picture, kinetically speaking, Sheffield's barrel pointing away from his body would actually decrease energy. But that's not really his hammer. This is.)
The problem with Baez is that there really isn't a great comp for his body type and hand load. He's not a massive guy and his hammer angle is radical by standard swing methods.
Two guys with pronounced hammers and similar body types are David Wright and Josh Donaldson. Neither takes his hammer to the extreme that Baez does, but both can help give us an idea of Baez's future and what adjustments he needs to make to become a star now instead of later.
Wright is an example if everything breaks right, but the comp starts to break down with his understanding of the zone—he has a .377 career OBP. Baez has a long way to go in that respect, however Wright and Baez's ability to generate power, particularly at such a young age and with similar builds—Wright hit 26-33 home runs in five out of six years between his age 22-27 seasons—is intriguing, but also a potential warning. As the body gets older and starts to break down, a large hammer can be hard to maintain. (Wright is currently slugging .374 and only slugged over .500 once since he turned 28.)
On the flip is Donaldson, who should serve as another kind of warning or maybe an example of what is in for Baez if he doesn't alter his swing sooner rather than later. Even with a less pronounced hammer, it took the A's third baseman until he was 27 to break out. A former Cubs farmhand, Donaldson found new life in Oakland after making a few swing adjustments and changing positions, leading to his incredible 2013 season.
Now, in pretend-land, if Baez were to put on 15-25 pounds and change his load's timing, Jose Bautista is actually a strong comp, but also another warning of late breakout potential if Baez doesn't make swing adjustments early in his career.
Bautista broke into the league in 2004 as a skinny utility man, playing on four different teams his inaugural year. He didn't hit a single home run until 2006 when he hit 16, his career high … until 2010 when he launched 54 home runs, instantly becoming one of the scariest hitters in the game. Prior to his breakout season, the Blue Jays Manager Cito Gaston told him one thing: "Start early." It became his mantra.
In translation from coach-speak, the idea is that if you start your load earlier, you will be forced to move back more controlled before committing to a pitch, or not. This will allow you pick the ball up sooner and longer, giving you more information than a hitter that "jumps" at the ball. Basically, you are generating a similar amount of power back while still being in enough control to be direct with your hands and in turn your bat head. Think of it like a lion slowly coiling down as it prepares to pounce versus a trampoline. One is a controlled build up of energy, the other a bunch of springs just bouncing up and down uncontrollably.
Add a spring training weight of 215 pounds, and it became clear that the combination of a controlled linear weight transfer back and increased muscle allowed Bautista to be not just a slugging monster but one with a purposeful swing.
Great hitters combine disgusting linear weight transfer, while also maintaining their weight "behind the ball"—picking up pitch type, break, and location well before they commit to the ball—and a complete instinctual knowledge of whether or not that pitch is in their hitting zone (hot zone) with slight adjustment making from pitch to pitch, often depending on counts and situations. Add a flawless swing and you get Miguel Cabrera.
(Miggy even goes as far as to take away his leg kick and slightly lessen his hammer in two-strike RBI situations. By simplifying his load, he shortens his swing, choosing to put the ball in play over potential power. Even then, he creates enough bat speed to go #YABO.)
The problem with Baez's hammer is that it is solely a power generator—it not only rushes him to make a decision before he is able to recognize pitch type and location, but it's also so powerful it makes his swing extremely hard to control, "full of holes." Assuming Baez doesn't figure it out—which, to be clear, he still may given his minor league track record—for him to take the next step, he will need to lessen his hammer to a more reasonable angle, which will shorten his swing, but decrease his power potential. A similar adjustment was made by fellow top ten prospect Joey Gallo this past off-season, leading to a breakout 2014 campaign. This is promising, but also necessarily less thrilling.
A comp that I didn't mention above, but one that has me intrigued, is early years Manny Ramirez and the adjustments he made to his load later on. He lessened the size of his front leg kick and also decreased the angle on his hammer, shortening his swing and allowing him to let the ball get deeper before committing to it.
Baez is both a special and limited hitter because of Newton's Third Law of Motion. But as my junior high science teacher used to say, "Science never sucks." (Because it's pressure change, you see.) As a Cubs fan, I'm hoping the same of Baez.
Top image credit: Brian Kersey / Getty Image Sports