Donald Trump’s power handshakes are weird as hell.

Trump is a walking, talking airport business book—a semi-sentient Rich Dad, Poor Dad—so it should come as no surprise that he is absolutely obsessed with power handshakes, which he thinks communicate dominance. But in reality they’re just silly.

The first major power shake of Trump’s presidency was granted to Supreme Court nominee Neil Gorsuch.

And on Friday Trump struck again, this time shaking, gently patting, and violently pulling Shinzo Abe’s hand for several seconds, to the increasing consternation of the Japanese prime minister.

But as the great Dan Amira noted back in 2012, Trump has been dishing out weird-ass handshakes for years. There are some lessons you can take from looking at some of Trump’s great handshakes. From his weird shake with Mitt Romney, you learn that he refuses to be the first person to end a handshake. You also learn that the tug is the central motif of the Trump handshake—he pulls in Romney as if to say, “You are not the boss. I am the boss. Even if you become president, I am still boss.” Amira called this technique the “pull in,” which is both gross and accurate.

But Trump still hasn’t topped his weirdest handshake, which was given to Apprentice winner Bill Rancic. There’s still time though—Prince Philip better watch out.