On April 14 in 2017 Anno Domini, in the fourth inning of a game at Dodger Stadium in Los Angeles, the City of Angels, Clayton Kershaw faced Paul Goldschmidt with a runner on first base. Kershaw's first pitch, as you might imagine, was a 90-mph slider that Goldschmidt could only foul off.
But then, strangely, Kershaw threw three pitches off the plate -- two of them outside, one inside and in the dirt. And Goldschmidt, being a man of discerning tastes, let them all pass.
Kershaw promptly threw a 90-mph slider down and in, the place where he makes his living, a kryptonite pitch even for the likes of Goldschmidt, who swung and missed. The count was full.
And then, the most miraculous thing happened. Kershaw threw a pitch off the plate and a little bit low. Goldschmidt did not swing. And that, by the rules of the great game of baseball, means that Kershaw walked Goldschmidt.

It was the first walk of the year for Kershaw, who allowed just one run and four hits while fanning eight in the Dodgers' 7-1 win over the D-backs. That's impressive enough, though there are others -- Felix Hernandez and Noah Syndergaard among them -- who have not walked anybody yet.
More to the point: It was the ninth unintentional walk Kershaw has thrown in the past calendar year. Nine.
Nine walks in 155 regular season innings (Kershaw was a bit wilder in the postseason) is fairly impressive. It's not quite unprecedented -- Carlos Silva of Minnesota walked just nine in a full 2005 season of 188 innings. Men like Slim Sallee, Babe Adams, Cliff Lee and Phil Hughes have had low-walk seasons.
But no one with the roller-coaster stuff of Kershaw has ever walked so few.
The thing that's so wonderful about Kershaw is that he does it simply. He basically throws three pitches. Kershaw has a changeup that he will throw maybe once a game -- he has not thrown one yet this year. Basically he throws a fastball at 93 or 94 mph, a slider at 90 mph and a big, gorgeous curveball at about 75 mph. That's the whole arsenal. Of course, the slider looks exactly like the fastball until it bends, and the curveball is perpetually surprising. Still, that's the whole Kershaw oeuvre.
And here's the thing: most of the pitches Kershaw throws are not actual strikes. Here's his pitch chart from 2016, courtesy of Statcast™.

It shows that 55 percent of the pitches Kershaw throws are out of the zone -- and more than a quarter of them are down and away to a lefty, down and in to a righty. So how does he not walk anybody? I did a podcast the other day with the great Hank Azaria, a gigantic Mets fan, and he seemed stupefied when I told him that for pure stuff, I (and most scouts, I imagine) would take Syndergaard over anyone in baseball.
"What about Kershaw?" Azaria asked quite reasonably.
But it isn't stuff that makes Kershaw Kershaw. Yes, of course, he has great stuff. But you see those pitches in the bottom left quandrant, 25.9 percent of the pitches that Kershaw throws? He makes those looks like strikes. That's the story.
There's a famous moment in magic (did I mention that I'm writing a book on Houdini?) where the master of closeup magic, Dai Vernon, fooled Harry Houdini with a card trick. Houdini always said that if he saw a trick three times, he would know how it was done. Vernon had Houdini sign a card and he put that card in the middle of the deck. Instantly it popped to the top. Houdini had him put it back in the middle of the deck and again it instantly went to the top … and again … and again … and again … eight times in all. Houdini boiled. But he could not figure it out.
That trick is called "The Ambitious Card," it's now a classic of magic, and it's basically what Kershaw does with his pitching. He shows the trick. And he shows it again. And he shows it again. But nobody can figured it out. Kershaw throws the ball outside of the zone over and over -- and hitters keep swinging and missing or making weak contact. Last year, hitters swung at 51.5 percent of Kershaw's pitches -- the second-highest swing percentage in baseball. But their contact percentage on balls out of the zone was just 49 percent  -- the second-lowest percentage (behind only the heartbreakingly great Jose Fernandez). They keep swinging. They keep missing.
Kershaw does this dark magic with a combination of velocity, movement, tunneling (each type of pitch comes out of his hand in precisely the same way), pitch ordering, sleight of hand and just a whiff of sorcery. He throws his pitches so close to the plate that they look like strikes no matter how well you've scouted him, no matter how much you prepare, no matter how closely you follow the Ambitious Card.
And that's why nobody walks against Kershaw.