Right when a curveball crosses the plate, the spinning of the seams tricks a hitter’s brain into thinking the ball is diving at a steeper angle than it really is. In the video above, you can see the same illusion at work — the circle is dropping straight down the screen, but its spin makes it seem like it’s moving to the left.
This is a well-known phenomenon called the curveball illusion. In a recent paper, a group of University of Rochester cognitive scientists conducted some tests to propose a new model of how the human brain uses motion to estimate the location of an object — and explain why it can sometimes be tricked.
They did so by carefully tracking the eye positions of study participants who watched videos of the curveball illusion and the related phenomenon of “peripheral slowing” (in which the circle about 1:10 into the video appears to spin more slowly when you’re not looking directly at it).
They argue that both these illusions — which only occur when an object enters your peripheral vision — are caused by assumptions your brain makes about position when it doesn’t have good data and can’t see the object clearly. In essence, it uses what’s called a Kalman filter: an algorithm that involves collecting a bunch of noisy data and making the best possible estimate based on all of it.
For months, their front-office executives debated the merits of Ike Davis and Lucas Duda. Davis was a former first-round pick whose career had been stymied by injuries and a plummeting batting average. Duda, a lower-round pick, had worked his way into the lineup but did not have a great batting average, either, or an extensive track record.
Both were left-handed power hitters, and they were close in age. But one clear advantage Duda had over Davis was better exit velocity when he connected. Given regular playing time, the Mets projected, Duda could develop into an elite slugger.
So a year ago they kept Duda and traded Davis, and Duda flourished. In 2014, he hit 30 home runs, drove in 92 runs and established himself as one of the team’s core players.
The challenge now for teams is how to consistently use exit velocity in a smart way. The challenge for fans is to become familiar with yet another of the advanced statistics that are rapidly changing the way people think about the game. Exit velocity is already being mentioned during game broadcasts.
So my initial puzzle as to why there was such a great difference in distance between these two home runs has been resolved. Multiple analyses using both Home Run Tracker and StatCast data show the primary reason for the different distances is the backspin. Everything hangs together nicely. In fact, the closeness of the StatCast distance to the independently determined distance from Home Run Tracker provides additional confirmation that the TrackMan algorithm for extrapolating from the measured trajectory to ground level is very robust. The StatCast era is upon us, and it will be very exciting to see what new things it will teach us about the game of baseball.
No such thing as grit? The science says otherwise:
If you detect something profound in the NCAA tournament, there is no need to apologize, because you are right, according to renowned neurobiologist Angela Lee Duckworth. A MacArthur Fellowship “genius grant” recipient who has her own research lab at the University of Pennsylvania, Duckworth studies traits that predict achievement, and her special focus is on the quality known as “grit.” It’s not just a descriptive term the way Duckworth understands and employs it.
“Grit is the tendency to sustain interest in and effort toward very long-term goals,” Duckworth writes.
She has developed a measurement for it by studying a range of achievers from West Point cadets, to National Spelling Bee winners, to the Seattle Seahawks, and is at work on a book about it. Her work shows that it’s a more important factor in success than talent, IQ or privilege.
In 2013, Seahawks Coach Pete Carroll saw a TED Talk by Duckworth, who is a Harvard- and Oxford-educated psychologist, and became fascinated. They began a series of conversations that helped Carroll refine what the Seahawks look for in players. Early in her research career, Duckworth developed a questionnaire to turn grit into a metric: By scoring the answers to a dozen queries, she rated people on a scale of 1 to 5. (I got a 4.3).
What Duckworth didn’t know was whether grit could be taught as well as measured. Carroll assured her that it could be: Coaches do it all the time. He offered up the Seahawks as a kind of laboratory for her. Duckworth will be visiting them in May. Duckworth is deeply interested in how to teach grit, because she did a stint as a public school math teacher in New York. At the heart of it is the ability to respond to failure or adversity, rather than give up.
Ignore the column’s emphasis on basketball; focus on grit, the greatest of all virtues.