Tim Chu
Cameron Sczempka (12) powers through a baseball swing during the analysis of the three sports article on Jan. 25.

Baseball

The old adage may indeed be accurate, and here’s why: baseball is a game of reads. As soon as the ball leaves the pitcher’s hand, batters have to use experience and smarts to predict whether the pitch will curve, how fast the ball is moving, and where it will end up. These factors determine how they swing at the ball, or at least where to swing the end of the bat.

But besides the mental challenge, the physics of the ball-and-bat contact is crucial to the game and fundamental to its difficulty. The bat speed required to counter the momentum of an 85-mph fastball is much greater than that needed to make a stationary golf ball fly. From the vertical to horizontal position, the swing of the bat doesn’t lose much potential energy, and thus gains little kinetic energy. So most of the energy exchange in the motion of the bat is produced by the batter’s legs, torso, and, if he’s a little out-of-practice, arms. This central rotation is required to really “hit” the ball, and not just throw the bat up and let the ball make contact.

Not to mention that the cylindrical shape of the bat produces many more angles of contact, and thus more varied directions that the ball can travel in, compared to the relatively flat surfaces of a tennis racquet or golf club. This means that hitting the moving, spinning ball both accurately and to a great distance is difficult.

But the game takes this into account. Most batters aren’t targeting a certain spot or even a general direction, other than within the foul poles. Both golf and tennis place more importance on both landing zone and direction, and tennis even has a moving object involved. As far as physics can take us in sports, baseball is tough, but it may not be the toughest.

Golf

Golf may seem simple: take the oddly-shaped head of the club back, and follow through as you rotate your body. But as any player or hacker can tell you, the most effective way to accomplish this motion is anything but simple. The basic motion of the swing belies the complex stuff going on, the stuff that makes golf one of the toughest sports to play consistently well.

Course and conditions aside, the act of striking a golf ball has a simple goal: transfer the energy at the head of the club, which is significantly greater as club length increases, to a little urethane-coated sphere. The backswing gives the club, and the head of the club, potential energy. This potential energy is converted to kinetic energy if gravity is allowed to do its job. In fact, if the human body could act as a simple pendulum, the consistent striking of a golf ball would be an easy motion dependent only on clubhead mass, club length, and the angle at the top of the backswing.

But the way the backswing works involves a rotation of the lower body, a hinging of the wrists, a contraction of the shoulder muscles and the constant stability of the legs. If any of these movements in the backswing is mistimed or not replicated exactly in the follow-through, the golf ball can be mis-hit, given a sidespin, or whiffed completely.

The ways in which physics influences the ball after it is struck is a totally different side of the story. But the most important thing, the motion itself, features greater complexity than the short stroke of a racquet or the comparatively basic body rotation of a baseball swing. For proof, go to the driving range and look at the difference in people’s swings. The two-part motion of the stroke means greater time for even the minutest error—which, in golf, is the difference between a 250-yard drive and a duff to the junior tees.

Tennis

Tennis, the dark horse of this competition, bears little resemblance to sports like softball and golf. The short racquet length and wide target of the wire netting at the racquet head means that literal contact with a moving tennis ball should be much easier than hitting a baseball.

But tennis’ differences are also its difficulties. The most basic: players can move to address the ball. The inertia that running tennis players gain as they pick up speed in pursuit of a tennis ball is difficult to stop. After the stroke, tennis players generally move a few steps, a motion that makes the eventual change of direction to make another return that much harder.

On top of this is the timing of the tennis stroke. While baseball and golf get their energy from an initial rotation before contact, tennis players use the energy they have from their running motion and transfer it through their legs and arms to the ball itself. The relative complexity of the timing and position needed to deliver any real force to the moving ball makes tennis a complex sport to learn.

Beyond this, a wide target at the end of the racquet does not necessarily help a tennis player. Just hitting the ball may be easier than in baseball, but tennis players have the added difficulty of targeting. The surface area of the face means that there are many possible angles at which to strike the ball, and many directions it can take after the stroke. Because both sports prize accuracy and penalize landing outside a boundary, tennis requires a sense of the direction the ball is traveling and a conscious effort to redirect its momentum.

For our purposes, the wide racquet face may make it easy enough to survive. But as for physics, don’t let it be said that this is an

“easy” sport.