Development of new 9-ball test protocols for assessing expertise in cue sports

Abstract

Background This study aimed to develop new test protocols for evaluating 9-ball expertise levels in cue sports players. Methods Thirty-one male 9-ball players at different playing levels were recruited (recreational group, n = 8; university team, n = 15; national team, n = 8). A 15-ball test was administered to indicate overall performance by counting the number of balls potted. Five skill tests (power control, cue alignment, angle, back spin, and top spin) were conducted to evaluate specific techniques by calculating error distances from pre-set targets using 2D video analysis. Results Intra-class correlation analyses revealed excellent intra-rater and inter-rater reliability in four out of five skill tests (ICC > 0.95). Significant between-group differences were found in 15-ball test performance (p < 0.001) and absolute error distances in the angle (p < 0.001), back spin (p = 0.006), and top spin tests (p = 0.045), with the recreational group performing worst while the national team performing best. Greater inter-trial variability was observed in recreational players than the more skilled players (p < 0.005). Conclusions In conclusion, the 9-ball test protocols were reliable and could successfully discriminate between different playing levels. Coaches and researchers may employ these protocols to identify errors, monitor training, and rank players.

Can a Good Break Shot Determine the Game Outcome in 9-Ball?

“…After each break shot, the positions of all balls remaining on the pool table were digitized manually ( Figure 1 ). Firstly, the “perspective grid” was applied to calibrate the pool table and was set as 127 cm × 254 cm ( Pan et al, 2021 ) which was the dimension of a standardized pool table used in professional tournaments. Then, the “mark” tool was implemented to mark each of the ball remained on the table.…”

“…Top-view videos of professional 9-ball tournaments were downloaded and analyzed using Kinovea (version 0.8.27, available for download at: http://www.kinovea.org), a 2D motion analysis software which has shown good accuracy in measuring objects at an angle range of 45 • to 90 • (Puig- Diví et al, 2019). In a previous study on 9-ball test protocols, excellent inter-and intra-rater reliability was found in measuring ball movements from video recordings using Kinovea (Pan et al, 2021). After each break shot, the positions of all balls remaining on the pool table were digitized manually (Figure 1).…”

“…Based on coaching expert’s opinion, the position of the cue ball and the distribution of the remaining colored balls after the break are of key interest. To evaluate the ball positions and movements on the pool table, previous studies on cue sports ( Haar and Faisal, 2020 ; Haar et al, 2020 ; Pan et al, 2021 ) applied 2D video analysis which involved a digital camera and analysis software. Based on video analysis, one could quantify the end position of the cue ball after the break to examine if parking the cue ball near the center of the pool table would indeed indicate a good break shot as suggested by the anecdotal evidence.…”

Analysis of arm, back and leg strength on the quality of power control in billiard sports

“…One of the successes in making an accurate shot in billiards is power control [14]. With good power control, an athlete will be able to perform an accurate hitting technique as expected [14,15].…”

“…One of the successes in making an accurate shot in billiards is power control [14]. With good power control, an athlete will be able to perform an accurate hitting technique as expected [14,15]. The factors that determine the accuracy of shots in billiards are examined in relation to the physical condition components which include arm muscle strength, back muscle strength, and leg muscle strength.…”