The Most Important Concept In Chess

Prophylaxis is unquestionably the most important concept in chess. Chess.com's glossary defines prophylaxis as "seeing what your opponent wants to do and stopping it ahead of time."

For less advanced players, a prophylactic move is the one that simply prevents a checkmate in one or a loss of a major piece. For example, a Scholar's Mate is quite common in the games played by beginners, but once they learn to ask themselves the most essential question in chess, "what my opponent is going to do?", it becomes very easy to avoid this or similar disasters:

However, for more experienced players, prophylaxis is a much more sophisticated concept. As they said about former world champion Tigran Petrosian, "he prevents his opponent's ideas before they even think of them." When the famous Soviet coach IM Mark Dvoretsky discussed prophylaxis in chess, he liked to demonstrate it with games by GM Anatoly Karpov. Indeed, prophylaxis was the cornerstone of Karpov's play. Here is one such example from Dvoretsky's book:

For Dvoretsky, prophylaxis was the backbone of his teaching method, and I remember a funny episode that occurred during a training camp for the top Soviet Juniors in January 1985, over 40 years ago. He showed us the following position. Try to find the best move for Black:

The game concluded this way:

Dvoretsky had barely set up the position on our big demo board and offered us to find the best move for Black, when the then 15-year-old Vasyl Ivanchuk yelled: "It is 12...Re8! preparing e6 and Bf8". Everyone (including Dvoretsky) was shocked! How is it possible to find such a deep idea in just a couple of seconds? Then, Dvoretsky asked: "Vasya, by any chance, did you see this game before?" Ivanchuk was visibly embarrassed and answered "yes" very softly. "Then why did you spoil this exercise for everyone else?" Dvoretsky asked, clearly upset. "I was just very excited when I saw a familiar position," Ivanchuk replied, causing everyone to laugh, and the incident was over.

I remembered this old story when I saw the following game from the 2026 TePe Sigeman Chess Tournament:

The last two diagrams look very similar, don't they? Of course, GM Nodirbek Abdusattorov either knew this Re8! idea from Dvoretsky's book, or simply found it over the board. By the way, it is not the only example of prophylaxis in his games played in this tournament. Here is another interesting episode:

Can you figure out why the natural move 58.Qf6 would be a huge mistake, which would allow Black to escape with a draw?

Abdusattorov correctly figured out Black's devilish trick and prevented it with the calm move 58. Kg1!, keeping a winning position. Nevertheless, he later made a mistake, and GM Andy Woodward's very creative defense was rewarded.

As I mentioned at the beginning of this article, prophylaxis is by far the most important concept in chess. You are playing against an opponent who is trying to do some harm to your position with every single move. So, if you forget just for a brief moment to ask yourself what your opponent wants to do and then prevent the possible damage to your position, then you'll pay the price.

Sometimes, even experienced grandmasters forget about this simple rule:

The lesson is quite simple here: always monitor your opponent's ideas and intentions! Whenever you see danger, take some action to prevent it.