The Astros asked their MLB scouts to try to steal signs from the dugouts, possibly using cameras to do so. Kevin Goldstein, who came up through Baseball Prospectus, sent a email to scouts:

Goldstein, who did not return a message seeking comment, wrote in the email: “One thing in specific we are looking for is picking up signs coming out of the dugout. What we are looking for is how much we can see, how we would log things, if we need cameras/binoculars, etc. So go to game, see what you can [or can’t] do and report back your findings.”

ESPN.com

It’s the camera comment that’s problematic. No one would complain if a scout picked up on a sign from the dugout. Aiming a camera at the dugout is a different story.

In information theory, the concept of entropy deals with the number of bits needed to encode a language. Morse code provides a nice example of this, as a bit is represented by a dot or a dash, and four bits can represent all letters in the alphabet.

The entropy for the sign language used by teams should be pretty low. On offense, managers are calling for takes, swings, hold the base, steal a base, hit and runs, bunts, etc. To make the language tougher to understand, teams add noise. Watch the third base coach go through signs, and you will discover that most of the movements he makes are superfluous. There are two bits that matter; the indicator, which conveys that the real sign is coming, and the actual sign itself.

This is the kind of problem that an AI algorithm should handle well. Imagine the Astros get a feed from the opposing dugout for a three-game series. They code each set of signs with the outcome, then train an AI with that information. I suspect they’ll be able to figure out that the nose touch followed by the hand clap is the steal sign.

There are humans who are good at this, but they need to see lots of examples. Opposing teams can change things around, but they can’t do that too often, or their own players will miss the signs. That’s why MLB rightly bans electronic spying on teams. It’s too easy with the algorithms today to figure out what is going on in the other dugout.