The very heart of chess
You might think that tactics or strategy are the essence of chess. Yet even if you employ perfect tactics and strategy, the game will still be a draw, provided your opponent makes no mistakes. All games that do not end in draws are the result of tactics. But what makes tactics possible? The answer is simple: error. Not good play, but error lies at the very heart of chess. Without errors all games would be drawn.
On losing the world championship in 2013 to Carlsen, Anand commented, "My mistakes didn't happen just by themselves. Clearly, he managed to provoke them." Carlsen was asked: "It seems Vishy was not at his very best; he was nervous, he made one big blunder and some other big mistakes in the endings. To what extent do you think you were responsible for it, for bringing him into those situations?"
Carlsen: "I would like to take some responsibility for his mistakes (smile), that's for sure. It's been that way for me for a long time, I just play and... People just crack under pressure, even in World Championships. That's what the history shows, you just have to keep on pushing and eventually usually things go right. Obviously the blunders that he made, each of them are of course unusual in the sense that those aren't mistakes he usually makes, but I think it really has to do with being put under pressure. That's really all I wanted to do in this match, make him sit at the board and play for a long time."
Joe Wisenthal commented on the match, "This is, essentially how all the decisive games have gone. There’s a chance for a draw, and Anand cracks under the pressure, while Magnus plays flaw-free chess. Magnus is just crushing Anand on the psychological game. And he does it in multiple ways. For one thing, if you’ve been watching the game you see that Magnus frequently just gets up and walks away from the table after he moves, which has to be unnerving."
Tyler Cowen wrote, "Carlsen is demonstrating one of his most feared qualities, namely his “nettlesomeness", to use a term coined for this purpose by Ken Regan. Using computer analysis, you can measure which players do the most to cause their opponents to make mistakes. Carlsen has the highest nettlesomeness score by this metric, because his creative moves pressure the other player and open up a lot of room for mistakes. In contrast, a player such as Kramnik plays a high percentage of very accurate moves, and of course he is very strong, but those moves are in some way calmer and they are less likely to induce mistakes in response."
The moves that might not be objectively best but which pose the most problems to the opponents can be considered nettlesome moves. Carlsen navigates towards positions where there are no obvious moves. Rowson, "Being a great chess player is as much about sucking the greatness out of your opponents as it is about demonstrating greatness of your own."
Given that errors are central to chess at the highest level, as well as at every level below, what are the practical consequences? It means that playing chess can be seen as consisting of three strands: avoiding making errors, provoking opponent errors, and exploiting errors when they do happen. The first two of these are strongly linked to the psychological aspects of chess.