Decision-making in judo as transitions in interpersonal coordination patterns

The aim of this study was to examine dynamic decision-making in judo as transitions in the fighter-fighter dyadic system. We hypothesized that 1) symmetric interpersonal coordination emerges in a fight, and 2) throwing decision-making is expressed as transitions in dyadic coordination patterns and occurs due to attacking affordances in the form of relative body orientation misalignments. Twenty high-level judo athletes were paired according to official rules. In the control condition, five dyads performed displacement movements without attacking. In the experimental condition, five dyads engaged in constrained combat to throw the opponent. Participants' angular velocities were processed into relative angular velocities and running correlations (RC) as measures of orientation (mis)alignments and dyadic dynamics, respectively. Results reveal that both experimental conditions showed non-normal RC distributions (p < .001), negative skewness (control: M = -0.95, SD = 0.31; experimental: M = -0.096, SD = 0.31), and higher frequencies in the symmetric interval (0 < RC < 1). Despite significant differences between task distributions (p < .001), results supported the attraction towards symmetric coordination. Also, in the experimental condition, RC dynamics abruptly transitioned between coordination patterns with increasing relative angular velocity, as attacks disrupted coordination and defensive actions stabilized it. These results supported that attacking decision-making was induced by relative body orientation misalignments, highlighting that decisions in judo are embodied, shaped by contextual interactions, and guided by throwing affordances. This view contrasts with mentally predetermined ‘optimal’ decisions, as it is dictated by information-processing models of cognition and traditionally prescribed in practice.