Shortcuts to Winning

How does a player cheat at chess?

When playing on-line chess at home, on his or her computer, a cheater receives instructions, hints, and directions from a second computer, standing beside the first, that contains chess analysis software.

But how does a player cheat at chess over-the-board, or in-person? Often, the cheater will work with an associate, who will access that same software on a hand-held device and will then signal to the player the better moves. Or a cheater hides a cellphone in the restroom, and takes frequent breaks.

Magnus Carlsen, a 32-year-old Norwegian, and reigning Wor...