I don't think there as many comments in today's literature about chess "style" when discussing individual players as there used to be. World Champion and prolific author Max Euwe wrote a book about The Development of Chess Style that took a "ontogeny replicates phylogeny" approach--that is, the beginner mostly makes threats , like the players of earlier times, and if the threat is missed they win something. Gradually, the player gets more sophisticated ideas like Morphy (development without definite threats), Steinitz (defense, the two Bishops), etc. as he "grows up" in his chess knowledge and ability.
I think Euwe's approach had some merit, but I don't think that "style" was quite the right word in this context. I think a player becomes stronger the more possible ways he has of looking at a position. The more types of plan he can envision for both himself and the opponent, the more flexible he will be in his approach. Anyone who has studied the games and careers of the greats like Morphy, Lasker, Capablanca, Alekhine and so on, up through Kasparov, Kramnik and the other top players of today realizes that they all have the common factor of usually trying to play as the position demands, whether it's an attack on the King, winning material and defending for awhile, sacrificing material to gain other advantages, etc. All really strong players are, more or less, universal players.
Even so, we all recognize that it's the individual differences that make chess and chess players interesting. Somewhere I read a Grandmaster say that in a 40-move game, any GM would play 36 of the moves the same, because they're demonstrably the best moves; it's the other 10 percent that illustrate what one might call the player's "style."
"There are two kinds of people in the world; those who think there are two kinds of people in the world, and those who don't."
I was thinking about all this and it occurred to me that there might be a useful distinction between two types of chess players, albeit that it only matters when one has become a fairly strong player and gained some of the "universality" that all strong players possess. A lot of writers have tried to distinguish between "attacking" players (say, Tal) and "positional" players (say, Petrosian); but my distinction is between the "pressurizers" and the "opportunists."
A pressurizer is a player who, with either color, tries to put pressure on the opponent right in the opening. Prime examples among the World Champions would include Alekhine, Fischer and Kasparov. These players were always among the great innovators in the openings during their active careers and generally played the openings in a way that challenged the opponent early to play sharply and well or suffer some disadvantage or pressure. Fischer's use of the King's Indian and Sicilian Defenses throughout his career is an especially clear example of this approach. After the opening, depending on what happened, Fischer was willing to play any type of game according to the circumstances, which was one of the reasons for his success.
An opportunist tries to play solidly and well in the opening, including not usually playing the sharpest variations as White. Instead, this type of player wants to avoid disadvantage and wait for the opponent to make a mistake. Taking advantage of errors by the opponent is of course the essence of winning chess, but the opportunist takes less risk and forces fewer errors, in return getting into sticky situations less often. Examples would be Capablanca, Petrosian and the grandaddy of all opportunists, Ulf Andersson.
I don't think these distinctions are as clear today; with the rise of the computer-assisted full-time pro, all of the top 10 or 20 has had to have an element of "pressurizer" in their openings to stay alive among the elite.
At the club level I see these distinctions as still being much more valid and useful. At my club, for instance, there are some A-players and Experts who almost always answer 1. d4 Nf6 with 2. Nf3, avoiding all kinds of things that might turn the game into an early slug fest and just trying to keep White's normal edge until an opportunity comes along. On the other hand, 1. e4 players have a bit of a harder time doing this--most opportunists use this first move sparingly.
There are a number of approaches to trying to win a game of chess, and this is just one way of looking at it. Do any readers have thoughts on an alternative method?