The Astros were stealing signs before and during the world series they won, using a camera in center field. 

What I am wondering is, it's so easy to do this, and so easy to prevent, why don't teams prevent this sign-stealing by encoding their signs?   Create a code where one sign affects another sign.  Now a "1" doesn't mean fastball; it means curveball, or whatever.  It's so easy to do this.  You can make one sign mean a switch, or you can have dummy switches, and you can change the whole code during a game.  

Or, you can say, today each batter gets a sign switch on the first pitch.  Really simple.  Or you can say, today, in the third inning, the second sign is the real sign.  How hard is that?  Or, catcher walks to the mound and says, next pitch is a sign switch, and then the pitch after that is the real sign.  Or, today, if I rub my leg a certain way, it's a sign switch.  ANYTHING.  

It seems so stupid in this day and age to have the catcher making such obvious signs to the pitcher as "one finger means fastball."  It's so easy to steal signs like that, and so easy to prevent it.

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