How to Cheat at Chess
Cheating in chess is widely deemed to be the greatest threat to the future of chess. Many amateurs and even many professionals regularly state that cheating is rampant. Accusations pervade every level of chess from the lowest levels of online chess to the world championship where in 2006 Topalov rendered baseless accusations against Kramnik in "Toiletgate". Other baseless accusations have included those by Mamedyarov against Kurnosov regarding the below fine game played at the Aeroflot Open in 2009 and the recent ridiculous accusations against WGM Sandu in the 2015 European Women's Championship.
Although there is no doubt that cheating does occur, and that it is an important issue. I think the incidence of cheating is greatly exaggerated. When one considers how many millions of chess games have been played, the number of proven and even accused cases of cheating is marginal. In fact, I would argue that there is a greater danger to chess in the perception of cheating than in the actual act. I know multiple players who have irrationally avoided playing competitive chess because they fear playing cheaters. Personally, in hundreds of tournament games, I have never once felt the least suspcicion that my opponent was cheating.
When I was ~17, I upset a 2200 player on the old USCF server. (Sidebar - Does anyone else remember that?!) I was about 1700 at the time. He sacrificed his bishop on h7, and I took the piece and managed to hold the position. I was very proud of my defense, but the entire experience was tainted by his ensuing profane accusations of cheating. That incident troubled me far more than any actual incidents of online cheating of which I have been victim.
That said, it's both amusing and valuable to discuss ways that cheaters cheat. It's only possible to prevent cheating by understanding it and instituting measures that target actual means of cheating. I fear there is every possibility of chess security resembling the TSA - more about the "theater of security" than actual security.
One of the most lighthearted means of cheating at chess is the act of relaying the moves between two opponents. This trick was once performed by American legend Frank Marshall against two US talents (I believe Isaac Kashdan and Reuben Fine...) in transit aboard a steamer to the chess olympiad. Marshall challenged them saying that he could play them both simultaneously and claim at least a 50% score against them. To do so, Marshall placed his opponent's in separate rooms and simply passed their moves back and forth. In fact, they were playing each other and Marshall was guaranteed one win and one loss or 2 draws from the games! The same trick was recently used by English magician, Derren Brown, as part of his act.
A similarly famous case that wasn't actually cheating occurred in the Goteburg Interzonal between Soviet and Argentinian players when the Argentinian players collectively tried a novel Sicilian variation they had prepared. The Soviet players were able to win all 3 games when the other two players took their cue from Geller who found the moves 11. Nxe6!? and 13. Bb5! in the below game.
I had a similar case in one of my games at the World Open this year. The players next to me played a theoretical line in the French Tarrasch with the White player clearly being theoretically prepared. My opponent repeated this line, and I was concerned that he would copy the better prepared neighboring player's moves, but he was oblivious to the shared opening and immediately went wrong and was lost on move 10!
Sandbagging is probably one of the most annoying and prevalent forms of cheating. Sandbagging refers to intentionally deflating one's rating. Usually, this is done to have a better shot at money or trophies in tournaments. In some cases, sandbagging involves intentionally losing games. This is clearly cheating and is usually catchable. I am personally aware of a young player being told by his parents to lose games so that he could play in the U800 section at the NY scholastic championships. Disgraceful. A more subtle case that I have also witnessed is a strong player accepting draws in favorable positions against lower rated players. It is hard to act on this as you can't deny a player the right to accept a draw or to play insipidly. Finally, the most common case I have witnessed is simply players refusing to play. Many studious players choose to compete only at major opens; by refusing to play rated games between major events, they are able to improve ahead of their rating and hopefully score big at the World Open, Millionaire Open, or the like.
Cheating in the John
While our first two types of cheating are non-technical, almost all cheating today centers around the use of computers. It is not necessary for a cheater to use assistance for an entire game. Using a computer at a single critical point in the game can have a dramatic impact on the outcome of the game. There is no easier way to cheat with a computer than by using one in a toilet. In recent cases concerning GM Nigalidze and FM Nastidis, a cell phone was used in the restroom at key moments in the game. Both players raised suspicion by extended absences after their opponent had moved. These cases are generally not cases of amateur cheating. These have been cases of IMs or GMs who, in an act of cowardice, resorted to using an engine. A truly amateur player would struggle to sufficiently augment their strength to affect the outcome of the game with limited consultations.
A Hidden Device
A more effective method of cheating is to hide a device on one's person. Proof of concepts exist for hiding chess engines in one's shoes or other apparel. This method is theorized to have been used by the infamous Borislav Ivanov. GM Tkachiev has also demonstrated proof of concept for using a wireless transmitter to receive moves from an accomplice. He provides a very compelling video showing that the method is actually quite feasible.
Assistance from Friends, Seconds, and Countrymen
Perhaps the easiest method of cheating is to receive visible assistance from an assistante. This method is proposed to have been used in GM Sebastian Feller's case where his coach Hauchard stood behind different boards during the Olympiad match to communicate moves. It is possible, but not so easy to develop an inconspicious code to transmit moves, but that is not entirely necessary. Former World Champion Anand has said that simply being cued thrice in a game that a strong possibility exists would be enough to improve one's play by ~100 ELO points. For instance, when a win or strong advantage is available, a second could enter the spectator's arena. It would be extremely hard to prove such cheating. After all, what could be more natural than a second entering the room to observe a critical moment.
The Electronic Scorekeeping Device
Electronic scoresheets are an extremely natural improvement over traditional written scorekeeping. It is easier to use, less prone to errors, suitable for beginners, and allows easy distribution of games. The problem with electronic scorekeeping devices is that they imply trust that the software is above board. Almost certainly the original software is, but the software can easily be cloned. Consider the below image... Do you see the suggested move? It is barely perceptible, but the g5 square has been highlighted to show an engine's recommendation. Such a subtle hint could be almost impossible to detect if you weren't aware of what to look for. In fact, this method was recently used in scholastics in Virgina where a player tried to pass off Fritz as the approved notation software enotate.
Fictional Results, Move Counts, Touch Moves, and the Like
One can also cheat by fictionalizing in game events. One might claim touch move or the lack thereof. One famous case is that of Kasparov vs. Polgar in which Kasparov claimed he had never touched a piece despite video evidence to the contrary. One can incorrectly include repetitions or other moves on your scoresheet to throw off an opponent who has made an error in notation. One could even fictionalize a scoresheet and record of the game. Such forms of cheating are quite common in scholastic tournaments, especially with young participants who aren't taking notation. This is why I always have both players report the results personally in tournaments I direct. As for myself, I try to always make sure my opponent signs the scoresheet to confirm the result.
Play Online Chess
I see a lot of complaints about cheaters in online chess. All I can say is that any idiot can cheat in online chess. What they get out of it, I don't know.
How NOT to Cheat - Use Drugs
One cheating method that doesn't work is drug use. Drug testing in FIDE events is one of the silliest things in recent chess memory. As one player said, if there were any drugs that would help, I would take them! Unfortunately, they don't exist
The good news is that cheating is preventable. In my opinion, most assisted cheating can be stopped with the following four methods.
1. Live transmission of games should be prohibited. Transmission of games should be delayed 2 or 3 moves to prevent assistance.
2. No electronic devices, except those provided by the tournament director, should be permitted in the playing area - this includes the restrooms.
3. Electronic jamming should be used to prohibit wireless transmissions in the playing area.
4. For high level tournaments, there should be no interaction permitted between the players and any persons not part of the tournament staff. Spectators should not even be visible to the players.
Cheating in chess certainly exists, but it is not rampant, and there are good means of preventing it. More importantly, it is worth remembering that cheating has been claimed to be the death of other sporting pursuits in recent memory. Cycling was infested with cheating in a way that would be incomprehensible in the chess community. Cyclists still cycle. In fact, there are probably more cyclists now than ever. Chess is still challenging and satisfying, it will remain so whether or not some choose to cheat.