The estimation of player positions is key for performance analysis in sport. In this paper, we focus on image-based, single-angle, player position estimation in padel. Unlike tennis, the primary camera view in professional padel videos follows a de facto standard, consisting of a high-angle shot at about 7.6 m above the court floor. This camera angle reduces the occlusion impact of the mesh that stands over the glass walls, and offers a convenient view for judging the depth of the ball and the player positions and poses. We evaluate and compare the accuracy of state-of-the-art computer vision methods on a large set of images from both amateur videos and publicly available videos from the major international padel circuit. The methods we analyze include object detection, image segmentation and pose estimation techniques, all of them based on deep convolutional neural networks. We report accuracy and average precision with respect to manually-annotated video frames. The best results are obtained by top-down pose estimation methods, which offer a detection rate of 99.8% and a RMSE below 5 and 12 cm for horizontal/vertical court-space coordinates (deviations from predicted and ground-truth player positions). These results demonstrate the suitability of pose estimation methods based on deep convolutional neural networks for estimating player positions from single-angle padel videos. Immediate applications of this work include the player and team analysis of the large collection of publicly available videos from international circuits, as well as an inexpensive method to get player positional data in amateur padel clubs.

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In rink hockey, it is not usual to find proposals of mini-hockey in early competition. This study aimed to analyse the effect of the manipulation of court dimensions and the number of participants on the motor behavior of players. Twenty-four rink hockey players (three girls and 21 boys; age: 7.1 ± 0.4 years) U8 category participated in this study. Three types of 3-min games were played twice, with 3-min breaks, following a random order: i) Four versus four (plus goalkeeper) on an official pitch (40 × 20 m); ii) Four versus four (plus goalkeeper) on a rink measuring 20 × 13 m, and iii) Two versus two (plus goalkeeper) on a court measuring 20 × 10 m. All games were video-recorded and a systematic observation instrument was used to register the actions using the Lince PLUS observation tool (v.1.2.0-2020). The individual technical-tactical behavioral variables of the court players were analysed, considering: (a) actions without the ball; (b) actions with the ball; and (c) final phase of ball possession. Statistical analysis was performed based on the Generalized Mixed Poisson Model. The results revealed that total actions were increased in both scaling situations compared to situation 1 in which young rink hockey players officially compete (S1 vs. S3; p <.001; Odds Ratio (OR) = 2,12) (S1 vs. S2; p <.001; Odds Ratio (OR) = 1,48). The results revealed that in small-sided games more affordances emerge concerning the official rules. The data obtained suggest that competition at this age on an official court (40 × 20 m) is not recommended for development of the variety of the set of individual technical-tactical behaviors.