Relationship Between the Relative Age Effect and Lengths of Professional Careers in Male Japanese Baseball Players: a Retrospective Analysis

Sports Medicine - Open

Table 3 Number of players grouped by 3 years for lengths of professional career

	1–3 years	4–6 years	7–9 years	10–12 years	13–15 years	16–18 years	19 years	Total	p	w
Q1 (Apr–Jun)	494	256	218	146	126	64	39	1343
[Expected]	528	228	187	181	129	69	19	1343
X ²	2.2	3.5	5.0	6.8	0.1	0.4	19.8	37.80	<0.001	0.168
Q2 (Jul–Sep)	460	252	180	134	97	59	30	1212
[Expected]	477	206	169	163	117	63	18	1212
X ²	0.6	10.4	0.7	5.3	3.3	0.2	8.9	29.48	<0.001	0.156
Q3 (Oct–Dec)	319	153	119	95	79	42	25	832
[Expected]	327	141	116	112	80	43	12	832
X ²	0.2	1.0	0.1	2.6	0.0	0.0	14.0	17.97	<0.001	0.147
Q4 (Jan–Mar)	327	141	116	112	80	43	12	831

The number in the second row shows the expected number of players calculated from the number of players in Q4 (Jan–Mar)
X ² chi² value, w effect size