NIU physicist: secret of Cubs’ success is science

June 22, 2015


Ask Northern Illinois University Assistant Professor of Physics Jahred Adelman about the successes of the Chicago Cubs during the early part of the 2015 season, and he might tell you it’s because of the organization’s scientific approach.

NIU Physicicist and baseball fan Jahred Adelman

NIU Physicist and baseball fan Jahred Adelman

“There are a lot of people who deal with data analysis in the same way that a physicist or scientist would really try and figure out the small differences in performance or signals from huge data sets of every at-bat, swing or ground ball,” Adelman says. “We have a general manager and manager in Chicago who adhere to this a lot more than the previous people who were running the team.”

A baseball aficionado and New York Mets fan, Adelman describes the sport as a “beautiful game” that allows people to watch and understand physics at work.

“The same motion that describes roller coasters, that describes rocket ships, that describes your car when you’re accelerating and when you brake really comes down to the same physics of hitting, catching and throwing a baseball,” he says.

Cubs players are performing more consistently and at higher levels this season, and it has translated to wins. Offensively, Anthony Rizzo is having a career year at the plate, and rookie Kris Bryant has made solid contributions as well. Both have shown explosive power at the plate and are reaching base often. Adelman explains their hitting in terms of simple physics.

“When you’re talking about hitting, the idea is to apply as much force to the ball to make it accelerate and go as long and far as possible. The ways that a hitter can do that is take a bat and swing the bat faster and harder because the harder and faster you swing, the more force you will apply to the ball,” Adelman adds.

Successful hitters like Rizzo and Bryant are aware of their strike zone and make consistent contact with the ball during their swing.

Anthony Rizzo squares up on a ball (Wikimedia Commons upload by UCinternational)

Anthony Rizzo squares up on a ball (Wikimedia Commons upload by UCinternational)

“Of course you can’t just take the hardest swing that you want because if you just swung as hard as you could, you would very rarely make contact,” Adelman says, noting Rizzo’s ability to modify his approach at the plate depending on the count. “One of the things that a good hitter will otherwise do is they will…choke up on the bat. If you choke up on the bat then you are going to have an easier time controlling the bat, but you are going to apply less force to the ball.”

He explains Rizzo’s combination of power and batting average by his ability to “square up” on the ball and hit it in the so-called sweet spot, even while choking up on the bat.

“If you hit the ball with the sweet spot of the bat, you convert as much kinematic energy from your swing and the bat as possible to the kinetic energy of the ball. If you miss the sweet spot, the bat has some remaining kinetic energy because it is vibrating, so that there is less energy available to the ball,” he says. “So for the most part it is really just squaring up on the ball. Other than using a heavier bat or choking up on the bat, what really differentiates the good hitters who have a lot of power is really being able to squarely strike the ball.”

The best pitchers are those who don’t allow hitters to squarely connect with the ball. Depending on their physical makeup, they will try to overpower hitters, change locations and speeds, or trick them with a breaking ball such as a curve ball or slider.

Cubs Manager Joe Maddon recently said pitcher Jake Arrieta has “borderline no-hit stuff” nearly every outing. His repertoire includes a four-seam fastball, sinker, slider, curveball and changeup. Arrieta is at his best when he induces ground balls and swinging strikes. To achieve these results, he mixes up his pitches to keep batters off balance.

His fastball averages between 93 to 95 mph and tops out at about 100 mph. Fastballs in the high 90s are difficult to catch up to as a batter, thus making it more difficult to make contact with the sweet spot.

“If you throw a four-seam fastball that seems to rise even if it doesn’t, it falls less than you expect it because you are putting backspin on the ball,” says Adelman.

Conversely, the sinker is a pitch that is released with the palm of the hand facing away from the pitcher. This causes the ball to drop as it approaches the batter, causing him to swing over the ball and miss, or produce a ground ball, rather than a line drive.

His slider-cutter averages 88 mph with a late break, and his curve sits at 80 with two-plane break, down and to the left.

Cubs pitcher Jake Arrieta fools a hitter with a curveball (MLB.com)

Cubs pitcher Jake Arrieta fools a hitter with a curveball (MLB.com)

“A curveball is generally curving for the same reason that airplanes take off. They are very, very different things, but in the end they both just come down to the flow of air over an object,” Adelman says. “If you spin the ball the right way, you push the air up and the air pushes the ball down or to the side.”

Generally, the amount and direction of the spin determines the amount the ball breaks as a result of friction with the air. The more topspin, the greater the air pressure difference between the top and bottom of the ball, and the greater the break.

With a changeup, the drop in velocity is caused by gripping the ball deep in the palm of the pitcher’s hand. Less finger contact means less torque and less velocity, so a batter expecting a fastball is fooled by a changeup thrown 10 to 15 mph slower than a fastball, and he’ll swing ahead of the ball.

Whether players know it or not, the fundamentals of the game are strongly rooted in science. To master them is to consistently achieve a high level of play.

So can science propel the Cubs to a World Series championship?

“There’s a part of me that wants to say that the Cubs defy all physics, and it all comes down to billy goats, which don’t necessarily adhere to the normal rules of science,” Adelman says. “I’m not sure how true that is, though.”

 

Just back from CERN, the European Organization for Nuclear Research in Switzerland, Jahred Adelman earned his Ph.D. from the University of Chicago, and his research interests include elementary particle physics, Higgs boson physics, top quark physics and hardware-based track triggers in addition to baseball.