TABLE 1.
Analysis of birth-date distribution by quarter of the year among Polish elite youth volleyball players.
| Q1 (%) | Q2 (%) | Q3 (%) | Q4 (%) | Total | χ2 | p | df | V | Effect | |
| Players not selected for the NVDP | ||||||||||
| Male | 818 (43.08) | 532 (28.02) | 328 (17.29) | 220 (11.61) | 1,898 | 285.1 | <0.0001 | 3 | 0.25 | Medium |
| Female | 745 (39.98) | 566 (30.39) | 317 (17.01) | 235 (12.62) | 1,863 | 158.4 | <0.0001 | 3 | 0.21 | Medium |
| Players selected for the NVDP | ||||||||||
| Male | 135 (42.86) | 91 (28.89) | 70 (22.22) | 19 (6.03) | 315 | 46.5 | <0.0001 | 3 | 0.27 | Medium |
| Female | 107 (37.02) | 88 (30.45) | 61 (21.11) | 33 (11.42) | 289 | 23.9 | <0.001 | 3 | 0.19 | Medium |
| Polish population born in 1989–2001 | ||||||||||
| Male | 779,527 (25.54) | 783,084 (25.65) | 792,715 (25.97) | 697,344 (22.84) | 3,052,670 | 35,957.7 | <0.0001 | 3 | 0.02 | — |
| Female | 739,516 (25.56) | 736,556 (25.46) | 757,265 (26.17) | 659,867 (22.81) | 2,893,204 | 3,988.4 | <0.0001 | 3 | 0.03 | — |
| OHT players vs. players selected for the NDVP Percentage deviations and standardized residuals | ||||||||||
| Male | +0.03% −0.09 | +1.8% +0.17 | −19.5% +1.49 | −38.8% −2.16 | 2,213 | 7.9 | <0.05 | 3 | 0.06 | Small |
| Female | −3.2% −0.33 | — | +8.9% +0.67 | −4.3% −0.26 | 2,152 | 1.2 | >0.05 | 3 | 0.05 | — |
χ23, χ2 test value; p, probability value; and V, Cramér’s V.