highly significantp < 0.05
Statistical analysis ( Table 1 ) using Welch’s two-sample t -test—chosen instead of the Kolmogorov–Smirnov test because the comparison involved mean possession values from two independent groups rather than full distributional shapes—confirmed that the difference was highly significant ( p < 0.05 ) with a moderate-to-large effect size (Cohen’s d = − 0.63 ), indicating that Euro teams systematically maintained higher possession prior to goals than their Copa counterparts. 3.2.