Cheating requires ingenuity since you have to obfuscate around the baseball arbiters and your opponents. The cheating issue du jour is the sign-stealing engaged in by the Red Sox of which baseball officials may have had a eureka moment of realization with the monitoring of the Red Sox (and others) clubhouses in the postseason.
For those who assume using technology to advance the cause is a relatively new approach I present a fascinating book by Dr. Rob Bauer of SABR where cleverness included even the use of a hidden telegraph wire whereby signs pilfered via binoculars could be transmitted directly underground to the coaches box – usually occupied by the manager.