Swinging is a dance with many different partners

When it comes to the art of hitting a baseball, there is more than one way to skin a cat. There remain, however, several non-negotiable absolutes that every hitter’s swing must contain if they want to compete for batting titles and home run crowns.

Over the course of baseball history, we have seen exceptions to pretty much every perceived mechanical rule. We can debunk these simply by taking a look at the swings of our game’s standouts.

They can stand with their elbow up like Evan Longoria or down like Mickey Mantle. They can "step in the bucket" like Edwin Encarnacion and Ted Williams. They can implement a massive leg kick like Josh Donaldson or choose to never pick their lead foot up off the ground as Albert Pujols has done at many junctures throughout his illustrious career.

These players break most of hitting's unwritten rules and are annual All-Star-caliber players. What they share in common is more interesting than their differences, however. In search of the indisputable mechanical musts shared by all exceptional batters, I partnered with Baseball Prospectus' swing expert, Ryan Parker, and embarked on a research expedition.

Ryan and I looked at the swings of countless MLB stars, past and present, and examined positioning at various points throughout this strong and visually stimulating athletic move. We evaluated several points during their swing – the moment the front foot strikes the ground and the hands are in the ready-to-launch position (slotted), the contact point and the follow-through.

The swing has endless additional components, and we purposely neglected to examine elements such as the setup and load. These are highly variable and should be celebrated for their spectacular diversity, but are not relevant for this analysis.

The similarities of elite hitters become striking at the point at which the front foot impacts the ground.

At this moment, excellent batters have their hands slotted between the back shoulder and the back foot. This is similar to the point when the archer can pull the string of the bow no further. He’s ready to fire and so, too, is the hitter. The back elbow is positioned roughly shoulder high, give or take a small distance in either direction, and the tip of the bat is somewhere over the hitter's head.

“From the slot position the bat will enter the zone almost tracking an outline of a Nike swoosh logo.” Ryan illuminated. “Before the hands enter the hitting zone, high-level hitters have already begun opening their hips and driving the back knee forward and down.

As an average hitter myself, I lacked that true back knee drive. I was stronger than Robinson Cano is, but he consistently strikes the baseball with substantially more force than I did.

Ryan continues.

“The hips are more flexible than most people realize and can actually rotate independent of the top half. This is where power hitters generate the torque that allows them to hit tape-measure shots. “

Hip flexibility is genetic to a degree, and the most gifted hitters have won both the genetic and mechanical lottery.

“The hips begin to rotate ahead of the top half. When the top half does begin to fire, watch the relationship between the back elbow and back knee. When the swing really gets going, you can see the back elbow and back knee driving forward in unison. The barrel of the bat turns behind the batter and is primed to enter the hitting zone.”

Before the hands move past the back shoulder, the heel of the back foot visibly comes off the ground. Raising the back heel does nothing in a vacuum. The heel comes off the ground because the knee is driving forward and the hips are unleashing all their torque. The power begins to transfer from the earth up through the kinetic chain and becomes accessible. It’s about to get violent.

Speaking of violence unleashed, see Harper’s knee and heel.

Here comes the moment of truth. Wood smacks horsehide flush and the batter experiences ecstasy.

Freezing All-Stars and Hall of Fame hitters precisely when they are impacting the baseball is a necessary exercise to study the inherent commonalities of their swings.

At the point of contact, the top (dominant) hand is in a palm-up position. Brace yourself if you’re a traditional hitting coach, I’m about to say something that will hurt your feelings. The best baseball swing is an uppercut. That aforementioned top hand is in a clear “uppercut punch” position, busting that old “swing down!” myth in the mouth.

We admire these men for the velocity of the ball off the bat, but what they all do after that captious point is more meaningful to the end result.

During their follow-through, these hitters continue their top-half rotation significantly past the point at which the bat makes contact with the ball.

Ryan suggests, “Too many hitters stop rotating on top for fear of flying open.”

It’s unlikely the great Ted Williams was bogged down by the Little League dogma.

We can use this as an opportunity to erase the old wives’ tale that flying open, or pulling the front shoulder and hip away from the location of the baseball, is about what happens after contact. It is not. Immediately after the ball leaves the bat, the back shoulder will often continue beyond the first-base line for a lefty or the third-base line for a righty. There is some variability based on flexibility of batter, pitch location, balance and more, but there is an absolute takeaway. From the waist up, the best MLB batters continue rotating after they have struck the baseball.

So there you have it. There aren’t many hard facts when it comes to swing analysis. If you need proof, watch Hunter Pence Samurai chop a pitch at his eyeballs out to right center field. We do have some rules, though, and they’re not the ones your Little League coach preached. It’s worth having a few bits of indisputable evidence in our notebooks, so when the world cries, “What’s wrong with Robinson Cano?” we can safely answer, “Nothing substantial.”  Check the video.