It doesn’t happen often, but it can be telling: managing partners or other law firm leaders abruptly jumping ship from their own firm for a competitor.

Milbank’s hiring of Irell & Manella’s former managing partner earlier this month is the latest example of a firm leader decamping for a rival. Other examples in recent years include leaders at Fried, Frank, Harris, Shriver & Jacobson; LeClairRyan; Crowell & Moring; and Montgomery McCracken Walker & Rhoads exiting for other law firms.