Bayesian Analysis of Skills Importance in World Champions Men’s Volleyball across Ages

Abstract

In volleyball, due to the sequential structure of the game, each outcome results from events that follow consistent consecutive patterns: pass–set–attack–outcome, serve–outcome and block–dig–set–counter attack–outcome. There are three possible outcomes: point won, point lost, and rally continuation. With the aim of quantifying the importance of volleyball skills, data of world champions of the male International Volleyball Federation tournaments for three age categories (Youth, Juniors and Men) were used to construct a transition matrix between subsequent moves and skills within the game. A Dirichlet-Multinomial Bayesian model was used to estimate the transition probabilities between the subsequent moves along with the marginal probability of success of each skill in the complex. The prior distribution of each transition probabilities between moves/skills was elicited to incorporate experts' opinion. For the final evaluation of the skills a simple Monte Carlo scheme was applied to obtain a random sample from the posterior distribution. The findings of the study indicate that the relative importance of volleyball skills is robust across world champions of different age categories. Slight variations are observed on specific skills. A new index (Quantile Mid-range Ratio) is proposed for highlighting skills that are valuable for team’s gameplay.

The contribution of skills in the interpretation of a volleyball set result with minimum score difference across genders

“…Male teams more often risk at serve in order not to lose the action directly. 12 This happens because of the overall performance in the skills of the complex 1 (side-out). Men present higher values than women in the quality of serve’s pass 4 and, consequently, in the effectiveness of attack 1 (after serve’s pass).…”

“…Further definitions for the evaluation scale per skill are included in Drikos et al. 12 about the serve, Costa et al. 13 about the attack, Palao et al.…”

A Bayesian Quest for Finding a Unified Model for Predicting Volleyball Games

“…Therefore, the use of a downweight parameter (similar to the power parameter) is recommended as in Drikos et al . (). In this way, most of the inference will be based on the actual data whereas a small portion of it will come from expert knowledge.…”

“…Moreover, additional covariates were not used here; therefore we have not touched on topics that other researchers have dealt with in the past (with simpler approaches), such as fatigue (Shaw et al ., ), the effect of service (Papadimitriou et al ., ; Lopez‐Martinez and Palao, ) and the effect of specific volleyball skills on final outcomes (Miskin et al ., ; Drikos et al ., ; Gabrio, ).…”

“…A similar approach was used by Drikos et al . () to analyse top level international teams in several age categories. Sepulveda et al .…”