RETI protocol was implemented over eight weeks, gradually simplifying the imagery script to focus on essential aspects of the free-throw (FT) shooting technique.

Using Virtual Reality (VR) technology, participants are fully immersed in an intense basketball game experience.

Week 1-2: Participants were asked to imagine a complete version of the FT imagery script included: a) Visualizing the court lines, the basket, and themselves standing at the free-throw line, focusing on their shooting technique. b) Imagining teammates and opponents positioned around the key, noting the main colors in the scene c) Imagining the coach standing on the sideline encouraging them, and paying attention to the sounds of the audience and the cheers from a close friend in the stands. d) Visualizing a high-pressure situation, experiencing the emotions felt during a real game with one second left on the clock, trailing by one point, with the game's outcome depending on their FT shot. Week 3-4: The exception of content "d"from the full script. Week 5-6: The exception of content "c""d"from the full script. Week 7-8: The exception of content "b""c""d"from the full script.

Free throw (FT) are a closed skill technique used for scoring points under practice, field study, or game conditions. Testing was conducted before, during, and after the intervention. FTs are typically awarded to players who are fouled while shooting, and the player takes the shot from behind the FT line, which is 15 feet away from the basket. Each successful FT is worth one point. In this study, to measure shooting accuracy more precisely, we employed the following scoring system: a shot that goes through the basket without touching the rim scores 3 points; a shot that goes in after hitting the rim scores 2 points; a shot that hits the rim but does not go in scores 1 point; and a complete miss scores 0 points. Each testing session comprised two sets of 10 FT shots, with a 15-minute rest period between the sets. The total score for each testing session was calculated by summing the scores from the two sets of 10 shots, resulting in a possible range of 0 to 60.

We utilized the Free-Throw Self-Efficacy (FTSE) scale developed by Fazel (2015) to measure participants' self-efficacy in basketball free-throw shooting, following the microanalytic technique guidelines proposed by Bandura (2006). Participants were asked to imagine taking 10 consecutive free throw and to rate their confidence in successfully making each of these shots. Specifically, they were asked to indicate how certain they were that they could successfully make 1 out of 10, 2 out of 10, and so on, up to 10 out of 10 free throw. Participants rated their confidence on a scale from 0 (completely uncertain) to 10 (very certain).