Aplicación de la Terapia de Aceptación y Compromiso (ACT) para el incremento del rendimiento ajedrecístico. Un estudio de caso

Context and Objectives

This case study presents the application of Acceptance and Commitment Therapy (ACT) to improve chess performance in a professional player. The participant is an elite South American chess player, age 27, who requested psychological services from a sports psychologist to improve his competitive performance. The chess player experienced a decrease in his chess performance, particularly during critical moments of competition.

The primary objective of the intervention was to improve the chess player's performance through the application of ACT principles, specifically addressing private events (thoughts, emotions, sensations) considered problematic that interfered with his performance. Experiential avoidance—attempts to control, eliminate, or avoid these private events—was identified as a functional mechanism maintaining poor performance.

The study aimed to demonstrate the applicability and feasibility of ACT in sports contexts and to explore whether modifying the functional relationship with private events (rather than their elimination) would result in improved sports and intellectual performance. The authors emphasize that this contextual-functional approach offers a valuable alternative to interventions focused exclusively on modifying positive cognitions or eliminating negative private events.

Method

Participant: M is an elite South American chess player, age 27, single, without children, from a middle-to-upper socioeconomic background. He has exclusive dedication to competitive chess, which has been his primary activity since childhood. He lives with his parents and brother in an environment he considers optimal. He possesses extensive chess training and is a high-level player.

The participant was contacted by the psychologist with the explicit intention of documenting a sports treatment that would be implemented congruently and respond to the specific needs of the case. During the intervention process, the participant developed receptivity and transparency toward psychological work, which facilitated therapeutic collaboration.

Design: A single-case design (N=1) was employed with measurements at pre-intervention, during intervention, and post-intervention phases. The study used a functional analysis approach, examining the problematic competition moments that affected M's performance. A detailed functional analysis of problematic competition situations was conducted through semi-structured interview.

The intervention consisted of 4 sessions of approximately 1.5 hours duration over a two-month period. The first two sessions were conducted with a two-week interval, and the two final sessions were completed during the thirteenth month of follow-up. Sessions were designed to allow M to practice the learned content between sessions.

Follow-up assessment extended 6 months after intervention completion. Objective performance measures based on international ELO rating (the official world chess classification system) were used, as well as self-report measures to assess changes in experiential avoidance, credibility, control of private events, and interference.

Intervention:

The intervention consisted of four thematic sessions structured around ACT objectives:

Session 1: Existence of unwanted private events and struggle to control them Functional analysis of the participant's problematic situations was presented. Work focused on how attempts to control private events during competition (thoughts, emotions, sensations) functioned as functional equivalents to the private situations themselves. An analogue exercise involving attempting to conceal numbers was used to illustrate the paradox of control: that attempts to suppress particular thoughts often result in their increase. Acceptance perspectives were introduced, characterizing what has been termed the "third wave of behavior therapy" as offering second-order change in functions discriminative for carrying out behaviors incompatible with adequate chess performance. Similar dialogues with relevant chess analogies were conducted.

Session 2: Difficulties in making important decisions during games Content from the previous session was briefly reviewed, and extensive work was conducted on how critical decision-making moments in games were interfered with by private events. Metaphors and experiential exercises were introduced to illustrate how cognitive fusion (the experience that certain thoughts were "true" or that certain private events needed to control behavior) interfered with decision-making. Perfectionist aspects were addressed. The "two climbers" metaphor was used to suggest that, just as in chess one must avoid playing with rules that are not useful in certain situations, one must also avoid playing as if thoughts and emotions needed to disappear prior to the action of playing.

Sessions 3 and 4: Clarification of values and possibility of initiating a new chess project During these sessions, M competed in several tournaments. Work focused on values clarification consistent with ACT. The final session work centered cumulatively on the values clarification phase of ACT. Emphasis was placed on M's important intention to undertake an educational project as a vital choice. It was proposed that the personal experience gained in selecting appropriate advice would be useful. Questions were posed about whether he would be willing to undertake action committed to his values even if this meant encountering difficulties. The participant demonstrated greater understanding of why a better understanding of his private events could result in behavior more consistent with his values.

Instruments and Measures:

1. Objective performance measure: International ELO rating, calculated using a mathematical formula based on victory points according to International Chess Federation (FIDE) regulations. The baseline was established three years before intervention. ELO points were recalculated for each tournament, allowing comparisons across time.

2. Acceptance and Action Questionnaire (AAQ-9): Spanish adaptation by Barraca (2004). It is a valid and reliable scale of experiential avoidance and psychological acceptance. Administered at initial assessment and follow-up (3 months post-intervention). Scores represent the degree of experiential avoidance.

3. Self-report measures during interview: Interference, credibility, and control of private events in difficult competition situations and normal situations were assessed. A Questionnaire of Acceptance and Action adapted for the Spanish population (Barraca, 2004) was used, which is a valid and reliable scale measuring experiential avoidance and psychological acceptance.

4. Functional analysis: A detailed functional analysis of problematic competition moments was conducted, identifying situations (S), behaviors (R), and consequences (C) maintaining poor performance.

Analysis:

Descriptive analysis of ELO score evolution across time was conducted, observing changes in performance during baseline (3 years prior), during intervention (2 months), and post-intervention (6 months). Changes in AAQ-9 scores pre and post-intervention were examined. Qualitative analysis of participant reports regarding changes in interference, credibility, and control of private events was also conducted.

Results

Chess Performance Results (ELO):

Figure 1 shows the evolution of ELO rating across time. During the 3-year baseline, ELO rating showed considerable variability, with approximate baseline mean shown. During the two competitions participated in during follow-up (corresponding to the last three months of the post-intervention period), a notable improvement in performance was observed.

Figure 2 presents the mean ELO points obtained per tournament during different periods:

• Baseline (3 years prior): 9.37 points
• 10 Best Baseline Tournaments: 4.31 points
• Intervention period: 6.2 points
• Post-intervention (6 months): 9.62 points

The two competitions participated in during follow-up constituted the best series of his chess career. The analysis revealed a notable increase in performance during follow-up compared to previous records. However, it should be noted that in practice the maximum number of ELO points that can be gained in a chess tournament is approximately 30 points.

Self-Report Measure Results:

Figure 3 presents scores on interference, credibility, and control of private events in difficult versus normal competition situations:

• Difficult competition situations (pre-intervention):

  • Interference: 96%
  • Credibility of difficulties: 86%
  • Control of difficulties: 80%

• Difficult competition situations (post-intervention):

  • Interference: 70%
  • Credibility of difficulties: 53%
  • Control of difficulties: 57%

• Normal competition situations (pre-intervention):

  • Interference: 35%
  • Credibility: 25%
  • Control: 21%

• Normal competition situations (post-intervention):

  • Interference: 25%
  • Credibility: 23%
  • Control: 23%

All scores decreased considerably. The participant reported that interference caused by his private events was much less, with AAQ scores decreasing, as shown in Figure 4, declining from 37 to 26 points.

Figure 4 shows AAQ-9 score:

• Pre-intervention: 37 points
• Post-intervention: 26 points

This represents a decrease of 11 points (approximately 30% improvement) in the experiential avoidance measure.

Discussion and Conclusions

The study presented a successful case of ACT application for novel topographical purposes that functionally remain framed under the lens of experiential avoidance. The brevity and impact of the intervention warrant emphasis, not as an exclusive characteristic of this case but as a defining trend in ACT research, where numerous successful interventions with minimal sessions are increasingly being found.

The results suggest that ACT was effective in improving the participant's sports performance. The decrease in AAQ-9 score (from 37 to 26 points) indicates a reduction in experiential avoidance. The self-report measures presented (with references to the participant's own behaviors during follow-up supporting ACT change processes) reflected significant changes in:

1. Interference from private events: Decreased from 96% to 70% in difficult competition situations
2. Credibility of private events: Decreased from 86% to 53% in difficult situations
3. Control of private events: Decreased from 80% to 57% in difficult situations

During follow-up, the participant reported feeling more comfortably adapted to his private events. Acceptance of private events during competition situations appears to have allowed the participant to maintain better performance. In his own words, he had learned to "compete" differently than he had previously.

It could be stated that M now had these private events rather than these private events having him in a position of "control." In the participant's own words, he had learned that during competition, "the only thing that matters is the position on the chessboard and not what occurs in his inner board." That is, he had overcome the acceptance of private events as problematic while simultaneously changing his regulatory behavior, fostering rule-following reinforced by the natural contingencies of action.

Both virtues and limitations of this work warrant mention. As virtues, we would note that this is a case study with a well-established baseline using objective measures that confirm a considerable increase in performance contingent on the application of the intervention. Furthermore, this study is correlated with a chess player in the framework of improving sports and work performance.

Future research will need to determine whether the ACT approach should be consulted as an alternative to psychological skills training. From this new point of view, a functional approach such as ACT would serve to correct the shortcomings of a "traditional" Sports Psychology approach. We maintain that to increase an athlete's performance (and by extension any other human activity), it is not necessary to change certain "negative" events to "positive" ones, since a negative private event does not need to reduce performance by itself. The key is when the athlete becomes fused with it and ceases to approach the relevant demands of competition, or alternatively, when he/she is more focused on avoiding and eliminating this private event than on performing adequate sports execution. Ultimately, to maximize performance, athletes must carry out behaviors relevant to the task at hand while placing private events in the place that corresponds to them at each moment.

Significance and Contribution

The work is significant in several aspects:

1. Novelty of application: This is one of the first studies to apply ACT specifically to improve chess performance, demonstrating the flexibility and applicability of the model to relatively novel domains.

2. Intervention efficiency: The intervention was brief (4 sessions over 2 months) yet produced significant changes measured in both objective performance (ELO) and self-report measures. This is consistent with emerging literature suggesting ACT can produce rapid and effective changes when applied in a focused manner.

3. Functional approach: The study demonstrated how detailed functional analysis of problematic private events allowed a targeted intervention relevant to the case, illustrating the utility of the contextual-functional model.

4. Multiple measures: Use of objective measures (international ELO) combined with self-report measures (AAQ-9 and interference/credibility/control of private events) provides comprehensive assessment of change.

5. Theoretical implications: The study supports theory that performance improvement does not require elimination of private events but rather a change in the functional relationship with them (acceptance and cognitive defusion).

6. Potential generalizability: Although a single case, results suggest ACT could be applicable to other sports contexts where interference from private events impairs performance, as well as to other domains of human performance.

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