[Editor’s note: This story has been updated to include a statement from the Astros.]



There is a broad story about this era of baseball that has yet to be told.



To this point, the public’s understanding of sign stealing mostly rests on anonymous second-hand conjecture and finger-pointing. But inside the game, there is a belief that is treated by players and staff as fact: That illegal sign stealing, particularly through advanced technology, is everywhere.



“It’s an issue that permeates through the whole league,” one major league manager said. “The league has done a very poor job of policing or discouraging it.”



Electronic sign stealing is not a single-team issue. Major League Baseball rules prohibit clubs from using electronic equipment to steal catchers’ signs and convey information. Still, the commissioner’s office hears complaints about many different organizations — everything from...