Strategy is concerned with the setting of an aim and the forming of schemes. Tactics are concerned with the execution of the schemes. Strategy is abstract, tactics are concrete.
Strategy forms an indispensable element in the proper treatment of a game and the same can be said about tactics. The player who can judge a position very clearly and who can adapt his plans to this position, will not be able to make use of these capabilities, if at the same time he is not proficient in tactics. As a rule a tactical mistake involves a much heavier punishment than a strategic one. A player wrongly attacking the Queen’s wing instead of the King’s wing will gradually get into difficulties, but anyone who does not foresee a mate in two moves, will immediately be defeated. Also, taking into consideration that tactical problems are more frequent in the course of a game than strategic ones, it is quite evident that the opportunities afforded the tactician will give him the advantage over the strategist. The development of tactical ability is, for the most part, a matter of practice.
So, while tactical opportunities are likely to pop up at any time in a game, a player who simply makes moves and hopes to win by random tactics is likely to lose to an opponent who has an plan behind his moves.
A plan is a set of actions based on the evaluation of the position. Planning depends on the correct evaluation of the position. And therein lies the problem; some positions are easy to evaluate and some are not. Things like weak squares, hanging or badly located pieces, pawn advantage, interaction of pieces, etc. all must be taken into consideration and the better the player, the more details he sees and the better his evaluation will be.
After evaluating the position, one should then create a plan. Normally, the best plans will be short, sometimes no more than 2-5 moves. The idea is to gradually improve one’s position.
For example, control a weak square, improve the position of a poorly placed piece, preventing the opponent’s counterplay, etc. By the way, When it comes to planning, if you can’t think of a good move and assuming there are no tactics in the position, C.J.S. Purdy suggests that a ‘plan’ might be as simple as determining your most poorly placed piece then relocating it to a more active position.
Of course, your plan should be realistic; something that is actually possible and not something you opponent can parry with impunity. Another point to remember is that your opponent can make moves, too. You have to pay attention to what he is planning and any threats he may have. This seems obvious, but if you’ve played more than one game of chess, you know what I mean. If his threats are serious, you have to first deal with them. But, also as Purdy has pointed out, in many cases threats are not really harmful and if that is the case, you can safely ignore them. It’s also important to keep in mind that during the game, the position changes and as a result, evaluations change and so your plan will have to change.
The first game Dr. Euwe examined in his book Strategy and Tactics in Chess was the following game. Unfortunately, it is not possible to give all of his notes which took up 14 or 15 pages, but I have tried to include the highlights. The instructive thing about this game is that the development of strategy is well defined, but that is a rare thing in most games. The strategic plan in most games will change frequently.
In this game the strategic themes can roughly be divided as follows:
Moves 9-11 White is driving the N from e5
Moves 14-18 White prevents Black from playing …c5
Moves 17-18 Black retains the 2B’s
Moves 18-20 Black attacks without playing …c5
Moves 21-24 Black plays to get in …c5
Moves 27-31 White plays to advance his f-Pawn
Moves 38- end Black plays to render White’s P-majority powerless