Why do people yell “CLOWN STILTS!” when Dirk Nowitzki hits one of those odd-but-deadly pogostick’d step-back jumpers? It’s simple really.

One of the most unconventional shots in the history of basketball is utterly by design. Dave D’Alessandro explains.

Initially, it was a typical set of shooting drills. Overheads with each hand to warm up. Catch and shoot from mid-range. Right-to-left and left-to-right crossovers at each elbow. High-arc stuff from outer space.

“And then, it just got crazy,” said Bob Salmi (of ESPN), whose pals rolled cameras and captured it from every angle. “It was a 50-minute workout, and one of the most bizarre things I ever saw in basketball.”

• A pirouette at the foul line, spinning 360 degrees off one shoulder and shooting; then reversing the spin and shooting. You get dizzy just watching it.

• One-footed jumpers — both right and left, both with leg extended and knee bent — from every mid-range angle, with or without glass. All of it is the kind of up-the-ladder stuff you pull out to finish a game of H-O-R-S-E.

• Something we’ll call the Groucho Marx: He’d take two long strides while still in a crouch, pick up a rolling ball, then shoot. Going both ways.

• The Eiffel Tower: Dirk spreads his legs as far as they can go (say, 2½ feet beyond his shoulder width), reach over to touch a foot with both hands, and then catch-and-shoot from that very awkward, open position. This is the one that makes every male shield his eyes.

It’s no accident that Dirk is basically unguardable.

During a particularly ridiculous effort from the Dirkus Circus I got to thinking, “Man, who… how can this shot be stopped?! It simply cannot be.”

Unless…

You try and think of another way. I can’t.