Position Evaluation (Part I). Level: Amateur

Not many fans talk about position evaluation. Curious because it is what should be done most during a game. And the classics were right when tirelessly asserting that "the strength of playing chess lies in the accurate evaluation of a position". Besides, whoever does not analyze a position until checkmate uses some form of abstraction to decide what should be played, from beginners to world champions, including chess engines. What differs are the methods and precision.

When talking about evaluation, terms such as equality, slight advantage, advantage, clear advantage and so on are used. These are conclusions that do not always include the explanation that supports them. Although we are interested in knowing the conclusions of others, we are more interested in learning to draw our own conclusions and that they are accurate.

Let's go by parts.

The evaluation is an estimate and comparison of the probabilities of success for each side from a position. In other words, the evaluation is a forecast based on a position’s inner-logic.

We talk about probabilities not in reference to human error, but to the limitations of the method to discern the position’s inner-logic. Indeed, the methodology to evaluate is an approximation by examining some elements, but there are cases in which –due to situations of extreme activity– such elements go to the background and the inner-logic can only be established –or approximated– by extensive and complicated calculations of variants. There is the question of why to use an imperfect method. The answer is reasonable pragmatism and efficiency, and because the accuracy can be improved with experience and study of the elements.

Let's look at a case.

In the position with Kh1 and Ph2 for White and Ka8 and Pa7 for Black, the one with the move has a decisive advantage. The evaluation can be based on a simple calculation or a count of the number of moves needed for each pawn to crown. But if we alter the position of the kings, it is possible that some may prevent the rival pawn from crowning, in which case the winning advantage would not necessarily be on the side who plays first, or there may be no advantage at all. Thus, we see that the inner-logic of that position is about two active and decisive plans, based on a pawn race, where if there is the possibility of interfering with the rival plan, the evaluation can be favorably altered. Such is the model to evaluate and, in a broad sense, play chess.

In the example above, there is little to consider to discern whether someone has an advantage or not. But the common thing is to find more variables, such as more pieces, more threats and counter-threats, more control over the squares required to fulfill ideas, and so on. Trying to analyze all or many of the possibilities can be impractical and generate confusion. Hence, over history, criteria have been developed to deduce the inner-logic by analyzing just a few elements. The equivalent of reasonable evidence for reliable forecasts.

The list of these elements:

1. Piece Activity;
2. Material;
3. Time;
4. Space; and,
5. Pawn Structure.

There are also other factors. For example, "erudition", based on learning, understanding, and assimilation of methods for identical or similar positions. Or "intuition", which suggests answers in unknown things or that go beyond the logic used. Kasparov, on the other hand, replaces the Pawn Structure with "Quality of Position", which is a way of relating the pawn structures and the squares under control with the mobility of the pieces, so that a better forecast of the activity can be done even in irrational positions; it is more complex but useful when in need to go deep in the position without resorting to complicated calculations. It is also worth noting that some pedagogues see the evaluation and the choice of the plan or the move as separate instances. It makes sense when the evaluation is simple or can be very precise, but when there is activity for both sides the evaluation is nurtured and corrected according to what is being discovered.

It is understood that when not considering each and every one of the possibilities, something important can be ignored, leading to the error in the conclusion. There is also a risk of error by improperly weighing an element. Therefore, the analysis requires considering the piece activity (the action of the pieces that’s influential in the opponent’s logical choices), in the form of threat detection and precise calculation, as a verification method.

As a logical development, the objective is to turn the activity into initiative (a set of logically related threats that are sustained by several moves), and the initiative into unstoppable (which finishes as checkmate). The idea is based on the premise that, in order to defend against threats, the rival must make concessions (in one or more of the elements listed), which in turn places us in a better position to increase the activity or initiative. It clarifies why the piece activity (the concept could also be called "piece and pawn activity", although the most common is "activity") is the most important characteristic in a position, be it in the opening, in the middlegame and, above all, in the ending. The rest of the elements gain meaning and importance because of the way they interact in the existence and persistence of activity or give clues to make forecasts.

The use of this logical framework (the analysis of certain elements plus verification by calculation) helps us understand the narrative on the board, the plot, the actors, the logic in their actions. But do not believe that it has always been this way, or that the criteria and their weighted value have been the same.

Here it is worth doing a brief review of how the current situation is reached because, although some ideas of the past have been left as incorrect, others have been enriched or validated for certain situations. And it is also worth it because the understanding of the game of many fans reminds the evolution of thinking in chess.

A little history.

The first experts in the game (XV-XVIII centuries) were genuinely intuitive and gave importance to obtaining material advantage or the concentration of forces and mobility as conditions to develop activity and then initiative, which then allowed tactical solutions. The defensive technique was not yet developed, so there were no defined limits for the concessions (such as weakening and material) made by to seize the initiative. The common thing was a win by whoever attacked first.

Philidor, in the mid-18th century, was perhaps the first to notice that pawn structures ("pawns are the soul of chess") determine the mobility of the pieces for both sides and that, by virtue of this, their disposition can determine the possibilities of active play. Armed with this knowledge it was possible to expand into and within the rival position by limiting the counter-activity. Thus, until the mid-nineteenth century, some experts used the pawns as closed phalanges seeking to create some breaking point by which to invade the rival camp, while others preferred open positions (where the pawns limit the mobility by little to nothing), typically giving material to take the initiative.

"The modern scientific theory in chess".

In the mid-XIX century, Morphy showed the healthy way of playing open positions, based on the economy of time in the development and execution of plans, the control of the center as a platform for mounting attacks, and justifiable concessions for the initiative. But Morphy did not state these criteria, and most likely he understood them intuitively. It was necessary that Steinitz, during the last quarter of the same century, pointed out that a mixture of positional considerations are (in fact: "may be") determining not only in the possibility of generating activity but also in restricting and extinguishing it.

"The modern scientific theory in chess" was an extension of Philidor's ideas, identifying more elements for the same purpose. Steinitz was a master in open positions and tactics (the "Austrian Morphy") but discovered that he could not always predict in advance whether they were favorable or not. Consequently, he analyzed the games of the best players of his time –with emphasis on Morphy’s– and deduced that certain considerations were key to knowing who was –and would be– better or worse. The idea of ​​finding and accumulating “small advantages” arises, in ways such as material, space, pawn structure, king’s safety, weaknesses in and around the pawn structures, control and occupation of the center, control and use of open files and diagonals, the advantage of the pair of bishops, etc. It was not a perfect method but more reliable than the intuition used by his rivals, and led him to the mark –not yet surpassed– of 25 consecutive victories in elite tournament games.

Steinitz proposed, among other things, that the search and accumulation of “small advantages” lead to great advantage, that the one with advantage must attack, and that tactics and attacks not based on advantages are inherently incorrect, and therefore extinguishable if not refutable. He showed that the brilliant attacks of his contemporaries, when not justified by the situation from which they were leaving, were successful only because of the weak opposing defense. Such demonstrations meant that he also had to delineate the principles of modern defensive technique, such as the precise detection of the components in threats, the economy in the use of resources, consolidation, and counterattack.

Steinitz's success in showing how to play from a position into a better position (positional game) and defend against "unjustified attacks" convinced many that the theory was valid. Tarrasch ("praeceptor germanie") took Steinitz's ideas and enriched them in books and articles until they became dogma (principles held by certain and undeniable). Lasker declared that he could turn any young man of medium intelligence into a master in just a few hours. Capablanca said that the game was exhausted by draw because if both masters played with positional correction there would be no winner. Certainly, Steinitz's theory was easy to understand and apply and seemed to predict everything logically possible. Some pedagogues of the game, even until the middle of the XX century, wrote that a well-played game should not need complex tactical solutions.

Not everyone in line.

But there were dissidents –at least partial– already in Steinitz's own time. Tschigorin, for example, did not agree with several rules applicable to any scenario, such as the advantage of a pair of bishops, although he did agree on the advantage of the center's occupation. Later, (“hypermodern”) masters like Breyer (“after 1.e4 White is lost”), Reti and Nimzowitsch questioned several considerations under the principle that each position has its own inner logic that is not transplantable to other positions of distinct characteristics, a bit expanding Tschigorin's thinking.

The argumentation on the advantage in the occupation of the center, sustained between classics and hypermodern, is useful in the development of thought in the game. The logic of the classics is understandable. To achieve an advantage it is necessary to achieve the supremacy of resources (material, space, time) in the disputed area. For this, it is desirable not to subtract resources in purely defensive tasks. Therefore, it must be played in search of the harmonic arrangement of pieces and pawns where, as a whole, they attack and defend simultaneously. Since the pieces have a greater radius of action in the center of the board, their location on the center should increase the likelihood that they simultaneously fulfill active and defensive tasks in the critical sectors of the board. However, given the "value" of the pieces, it is foreseeable that simple occupation will be repelled by threats from rival pawns. Therefore, it is necessary that the pieces occupy the center under the protection of a shield of pawns, or at least establish a combination of pieces and pawns in the center that is not advantageously expellable or disposable.

The hypermodern, meanwhile, argued that the strategy of invading the rival position (from the center or anywhere else) is based on increasing the activity of the pieces themselves by having more targets simultaneously within their reach (which increases the probability of the existence of tactical or positional solutions). Therefore, an early approach of the pawn and pieces to the opponent’s gives the latter the chance to develop and set up his pieces actively by targeting material already within their reach. Nimzowitsch put it in "first, stop, then, block and finally destroy."

The dynamism.

Classics and hypermodern were right and wrong because their ideas didn't always work. The missing consideration was seen in Alekhine's games and his time management: You can have a good idea, but not the time to execute it. Of course, there is no rule that gives one or several extra moves, but Alekhine showed that the activity, even in isolated ways, can achieve the effect of "subtracting" tempos from the rival by forcing him to purely defensive or innocuous moves.

While for the classics a position devoid of weaknesses was sufficient defense against the rival activity, Alekhine showed that even temporary discoordination can give cause for activity whose defense requires, at least, time concessions. If activity and initiative were built on the basis of siege against weaknesses before, Alekhine added time as an element on which to build the initiative, thereby reducing or denying static considerations by preventing the defense from consolidating.

Suddenly, it was no longer so healthy to allow the opponent to seize the initiative, regardless of how healthy the own position seemed to be: It was also necessary to consider the dynamic details that supported the activity and be prepared for complications and precise calculation of variants.

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End of Part I