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In many team sports, in which environmental change is constant, athletes selectively allocate attention between the approaching ball and other players, and constantly consistently making decisions regarding whom to pass the ball to. Few previous studies on decision-making in team sports such as soccer have included the ball reception phase. This study examined players’ visual search strategies during pass decisions. Using five-on-four soccer-specific film simulations from previously recorded real scenes, high-level players (HLPs) and middle-level players (MLPs) reacted to life-sized soccer scenes. We measured their visual search strategies in decision-making tasks involving ball reception and pass execution and collected their verbal reports. We employed a novel system wherein the ball is ejected toward participants according to the video clips in order to maintain perception–action coupling during the task. We found skill-based differences in decision-making accuracy, eye movement data, and verbal reports. HLPs demonstrated better decision-making than MLPs, and, in eye movement data, HLPs allocated more attention to nonmarked attackers ([ M] = 14.1, [ SD] = 4.8%, p < .001, η2 = 0.39), the teammate receiving the pass ( M = 18.4, SD = 4.3%, p < .05, η2 = 0.15), and opponents ( M = 14.6, SD = 6.3%, p < .05, η2 = 0.17) than did MLPs. Furthermore, according to verbal reports, HLPs tended to attend to information on opponent players. Thus, visual search strategies during ball reception suggest that the position and situation of teammates and opponents are the most important information sources for accurate and consistent pass decisions.

Wind-tunnel experiments were performed on Al Rihla, Telstar 18, Brazuca, and Jabulani, official match soccer balls used in the World Cup in 2022, 2018, 2014, and 2010, respectively. Aerodynamic coefficients extracted from wind-tunnel results were used to create computer simulations of trajectories of kicked soccer balls. The newest World Cup ball, Al Rihla, could be kicked for longer range compared to its recent predecessors. But there is also the possibility that knuckling effects at large speeds could be seen in the flights of the new ball kicked with little to no spin. Measurements were made of each soccer ball’s total seam length and seam width and depth. Two different measurement techniques were employed to assist with accuracy. Wider and deeper seams led to smaller critical speeds.

Five different soccer balls, each possessing the traditional 32-panel surface design, were tested in a wind tunnel. Only seam depth and width varied between the balls. Wind-tunnel tests and an examination of correlation revealed that seam width with a linear fit [Formula: see text] and [Formula: see text] was a stronger indicator of a ball’s critical speed than seam depth. Wind-tunnel data were used for computational modeling of many soccer-ball trajectories. It was determined that variations in seam geometry resulted in fluctuations up to 4 m in the horizontal range of hard-hit, no-spin kicks that travel approximately 68 m. Those seam geometry variations also contributed to lateral deflections up to 4 m for the aforementioned hard-hit, no-spin kicks.

The quantitative relationship between kicking motion and ball behaviour can be easily explained by detecting the impact point and foot posture. In previous studies, the impact point of a kicking foot was difficult to capture using visual tracking. Thus, a virtual surface modelling technique was applied in this study to clarify the differences in the three-dimensional foot speed, impact point and foot posture between straight, curve, and knuckle kicks in soccer, as well as the relationship between the kick motion and ball rotation. An optical three-dimensional motion capture system (VICON) was used to record the kicking motion. The impact points of the straight, curve, and knuckle kicks were found to be centrally located in the instep area, at a lower (more downwards) inside area, and at the medial area between the instep and inside areas of the kicking foot, respectively. Moreover, an impact with a greater ‘swing vector deviation angle (relative to the direction from the impact point to the centre of gravity of the ball)’ is necessary for ball rotation. The impact point detection method employed in this study can be applied to other ball impact estimations beyond soccer kicks.

The effect of a soccer ball’s surface texture on its aerodynamics and flight trajectory is not definitively known. For this study, five soccer balls were used, each having 32 panels with different surface textures. Their aerodynamics were examined via wind-tunnel experiments and then several non-spin trajectories were calculated for each ball. The results showed that the aerodynamic forces acting on a soccer ball change significantly depending on the surface texture of the ball, which in turn influences flight trajectories. The study contributes to an understanding of how a soccer ball’s surface influences the aerodynamics, which may impact the future design and development of soccer balls.

Aerodynamic coefficients were determined for Telstar 18 and Brazuca, match balls for the 2018 and 2014 World Cups, respectively. Experimental determination of aerodynamic coefficients prompted the development of computationally determined soccer ball trajectories for most launch speeds experienced in actual play. Although Telstar 18’s horizontal range will be nearly 10% shorter than Brazuca’s horizontal range for high-speed kicks, both Telstar 18 and Brazuca have similar knuckling effects due to nearly equal critical speeds and high-speed drag coefficients that differ by less than 10%. Surface comparisons suggest why aerodynamic properties for the two World Cup balls are so similar.

Wind-tunnel experimental measurements of drag coefficients for non-spinning Jabulani and Brazuca balls are presented. The Brazuca ball’s critical drag speed is lower than that of the Jabulani ball, and the Brazuca ball’s super-critical drag coefficient is larger than that of the Jabulani ball. Compared to the Jabulani ball, the Brazuca ball suffers less instability due to knuckle-ball effects. Using drag data, numerically determined ball trajectories are created, and it is postulated that although power shots are too similar to note flight differences, goalkeepers are likely to note the differences between Jabulani and Brazuca ball trajectories for intermediate-speed ranges. This latter result may appear in the 2014 World Cup for goalkeepers used to the flight of the ball used in the 2010 World Cup.

Kicking, and particularly foot–ball impact, is a fundamental soccer skill. To date, most studies of ball impact have examined only male players. However, gender differences among soccer players might affect kicking performance. The competitiveness of female players might therefore be enhanced by providing gender-specific training and coaching. Here we compared the technical characteristics of ball impact during instep and inside kicks between male and female players. Female players exhibited significantly lower ball velocity, foot velocity immediately before impact, striking mass, and average ball-to-foot velocity ratio than male players (p < 0.05). The ball-to-foot velocity ratio decreased as the distance of the impact point from the centre of gravity (CoG) of the foot increased. Our results suggested that training for female players should focus on making contact with the ball near the foot's CoG under various conditions.