## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Level of**} & \multicolumn{2}{c}{**Q1**} & \multicolumn{2}{c}{**Q2**} & \multicolumn{2}{c}{**Q3**} & \multicolumn{2}{c}{**Q4**} & \\  & \multicolumn{2}{c}{**Performance**} & & & & & & & & & & & & \\ \hline  & & \(n\) & \(n\) & \% & \(n\) & \% & \(n\) & \% & \(n\) & \% & \(\chi^{2}\) & \(p\) & \(w\) \\ \hline \multirow{2}{*}{Entire Sample} & Finalists & 167 & 41 & 24.5 & 41 & 24.5 & 58 & 34.8 \(\uparrow\) & 27 & 16.2 \(\downarrow\) & 11.563 & 0.009 & 0.26 \\  & N-Fs & 411 & 100 & 24.3 & 112 & 27.3 & 106 & 25.8 & 93 & 22.6 & 1.934 & 0.586 & 0.07 \\ \multirow{2}{*}{Subsample category} & \multirow{2}{*}{Finalists} & 40 & 10 & 25.0 & 10 & 25.0 & 11 & 27.7 & 9 & 27.7 & 0.200 & 0.977 & 0.07 \\  & & N-Fs & 189 & 52 & 27.5 & 43 & 22.8 & 50 & 26.4 & 44 & 23.3 & 1.243 & 0.742 & 0.08 \\ \multirow{2}{*}{Group Total} & Finalists & 127 & 31 & 24.4 & 31 & 24.4 & 47 & 37.0 \(\uparrow\) & 14.2 & 14.2 \(\downarrow\) & 13.315 & 0.004 & 0.32 \\  & N-Fs & 222 & 48 & 21.6 & 69 & 31.1 & 56 & 25.2 & 49 & 22.1 & 5.063 & 0.167 & 0.15 \\  & Finalists & 79 & 22 & 27.9 & 21 & 26.6 & 28 & 35.4 & 8 & 10.1 \(\downarrow\) & 10.772 & 0.013 & 0.37 \\  & N-Fs & 277 & 67 & 24.2 & 78 & 28.1 & 75 & 27.1 & 57 & 20.6 & 3.823 & 0.280 & 0.12 \\ \multirow{2}{*}{Junior Total} & Finalists & 20 & 6 & 30.0 & 8 & 40.0 & 4 & 20 & 2 & 10.0 & 4.000 & 0.261 & 0.45 \\  & N-Fs & 121 & 32 & 26.5 & 32 & 26.5 & 35 & 28.9 & 22 & 18.1 & 3.198 & 0.362 & 0.16 \\ \multirow{2}{*}{Junior Group} & Finalists & 59 & 16 & 27.1 & 13 & 22.0 & 24 & 40.7 \(\uparrow\) & 6 & 10.2 \(\downarrow\) & 11.305 & 0.010 & 0.44 \\  & N-Fs & 156 & 35 & 22.5 & 46 & 29.5 & 40 & 25.6 & 35 & 22.4 & 2.102 & 0.551 & 0.12 \\ \multirow{2}{*}{Senior Total} & Finalists & 88 & 19 & 21.6 & 20 & 22.7 & 30 & 34.1 & 19 & 21.6 & 3.909 & 0.271 & 0.21 \\  & N-Fs & 134 & 33 & 24.6 & 34 & 25.4 & 31 & 23.1 & 36 & 26.9 & 0.388 & 0.942 & 0.05 \\ \multirow{2}{*}{Senior} & Finalists & 20 & 4 & 20.0 & 2 & 10.0 & 7 & 35.0 & 7 & 35.0 & 3.600 & 0.308 & 0.42 \\  & N-Fs & 68 & 20 & 29.4 & 11 & 16.2 & 15 & 22.1 & 22 & 32.3 & 4.350 & 0.225 & 0.25 \\ \multirow{2}{*}{Senior Group} & Finalists & 68 & 15 & 22.1 & 18 & 26.5 & 23 & 33.8 & 12 & 17.6 & 3.882 & 0.274 & 0.24 \\  & N-Fs & 66 & 13 & 19.7 & 23 & 34.8 & 16 & 24.3 & 14 & 21.2 & 3.696 & 0.296 & 0.24 \\ \hline \end{tabular} Note: N-Fs = non-finalists; \(\uparrow\) = significant (\(p<0.05\)) over-representation of participants compared to the expected value in the quartile; \(\downarrow\) = significant (\(p<0.05\)) under-representation of participants compared to the expected value in the quartile. Expected quartile distributions were equal (i.e., 0.25%).  
\end{table} 
Table 2: Percentage distribution of RGs’ birth quartiles and \(\chi^{2}\) analysis by performance level (finalists vs. N-Fs) and competition format (individual/group) across the entire 2023 RG WCH sample, including junior and senior categories. participants aged 13 and 14, birthdate distributions did not significantly differ from expected values. However, a notable and atypical over-representation of athletes born in Q3 was detected in the 15-year-old subgroup, which may suggest intentional selection practices. Given their older chronological age compared to 13- and 14-year-old gymnasts, 15-year-olds likely possess more training experience and greater competition exposure [46], potentially enhancing the team's performance. At the same time, 15-year-old gymnasts born in Q3 are still relatively younger than those born at the beginning of the calendar year. Potentially, this could coincide with a less physically mature and more slender body type--features that may be preferred by coaches [47] and positively valued by judges [48]. It is worth noting that 15-year-olds represented the largest age group among juniors, comprising 51.4% of the category, followed by 14-year-olds (36.5%) and 13-year-olds (12.1%).