One of the things that helped me make the mental realization of how impractical a "style" can be came in an excerpt of an interview that I read last year; unfortunately I can't find it again to link, since I didn't bookmark it. In it, a grandmaster commented that style was largely an illusion among the top ranks of the chess world, as (for example) in a 40-move game, once out of the opening phase where both sides were relying on their book knowledge, only with perhaps 4-5 moves of the remainder of the game would there be any real divergence of opinion among GMs on the best move, leaving it open to the player's personal preference. This translates to roughly one move in seven having any real personal "choice" involved. (EDIT: see "A robust and deep insight on playing style" for the original quote, which I eventually found.)
At first, the concept sounded rather shocking to me and also seemed quite limiting for a player's freedom of choice. This gives you an idea of how I used to think about the phenomenon of playing styles: namely, that they reflect your innate abilities and thinking process and therefore determined almost every move of the game (or if not every move, perhaps one in two or one in three). The concept that the grandmaster presented, of style having an influence on play in certain unclear situations but not determining what should be played in most positions, was a new one for me. It's worth noting that a similar overall concept - that whatever move objectively works best in the position is what should be played, regardless of any set of general principles or beliefs about chess - is also the centerpiece of John Watson's masterwork Secrets of Modern Chess Strategy.
This is not to say that no such thing as a style of play exists. However, the perception of style is apparently greatly exaggerated at the top professional level; furthermore, as will be discussed more below, misunderstanding the concept can be a serious limiting factor for Class players. At the top levels, one can easily find examples of "positional, defensive" World Champions like Tigran Petrosian playing brilliant attacking chess and combinations, or "tactical, aggressive" players like Kasparov winning with relatively quiet, maneuvering games such as in the must-win final game of the 1987 World Championship. Certain strong players have deserved reputations for liking and playing particular position-types - and the openings that usually lead to those particular position-types - but that should not be confused with an inability to cross the tactical/positional divide when the position requires it.
The most important aspect of this for the improving player is not a theoretical debate about the styles of World Champions, though, but how the idea of "style" can affect our play and hold us back. Regardless of what we call ourselves, either tactical or positional players, I think mentally over-identifying with a style has some major detrimental effects on our performance. Most seriously from a practical standpoint during a game, it necessarily limits our ability to perceive and evaluate candidate moves as part of our thinking process. Moves that we consciously or unconsciously characterize as being outside of our style are either not examined or incorrectly evaluated, usually in a dismissive manner. What occurred in Annotated Game #2 when I wrongly and consciously dismissed a key move possibility, for example, was an early indication in my chess study that this was a problem for me. That and other examples from my analyzed games pointed out rather starkly that emotional and other illogical attachments or aversions to particular types of moves were measurably dragging down my performance level and causing me to lose games.
Moving beyond the general issues described above, here are some specific thoughts on how over-reliance on a "style" can hold you back as a player.
Tactical Style: this (as with any other style) will only get you so far as a player. It seems that low Expert level (2000-2100) is probably the top limit for tactical specialists; Michael de la Maza's well-known story is one anecdotal indication of this. (For those who are into statistics, you can look at his career record and make your own judgments about his playing strength versus various classes of players.) Naturally, a 2000 rating would sound good enough for a lot of people, but it is still short of mastery. Also, for those of us without hard-wired chess brains, the ratings ceiling for being a tactical specialist may be much lower than 2000. Here are some other typical limitations that may be associated with this style:
- When tactics are not currently present in a position, cannot identify a useful plan to make progress.
- Default plan is a kingside attack, regardless of the position.
- Neglects study of positional factors, since everything is about tactics.
- Neglects endgame study, because doesn't expect to make it that far, either winning or losing in the middlegame.
- Avoiding entering into tactical play, even when it would result in material or positional benefits.
- Being unwilling to undertake gambits or sacrifice material.
- Being unable to effectively conduct attacks on the opponent's king position.
- Having a tendency to draw a won position rather than win it.