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

Sports Medicine - Open

Table 1 Number of players divided into lengths of professional careers based on quarters of the birth year

Year	Q1 (Apr–Jun)	Q2 (Jul–Sep)	Q3 (Oct–Dec)	Q4 (Jan–Mar)
1	221	202	134	129
2	145	143	99	109
3	128	115	86	89
4	90	89	61	42
5	84	75	57	60
6	82	88	35	39
7	72	60	36	43
8	85	70	44	50
9	61	50	39	23
10	54	42	28	48
11	51	61	38	32
12	41	31	29	32
13	49	35	28	29
14	41	29	34	28
15	36	33	17	23
16	28	19	22	11
17	15	22	7	13
18	21	18	13	19
19	14	7	11	4
20	7	9	7	4
21	8	4	1	1
22	4	6	4	1
23	4	3		2
24		1	1
25			1
26	1
27
28
29	1

Year	Q1 (Apr–Jun)	Q2 (Jul–Sep)	Q3 (Oct–Dec)	Q4 (Jan–Mar)
1	221	202	134	129
2	145	143	99	109
3	128	115	86	89
4	90	89	61	42
5	84	75	57	60
6	82	88	35	39
7	72	60	36	43
8	85	70	44	50
9	61	50	39	23
10	54	42	28	48
11	51	61	38	32
12	41	31	29	32
13	49	35	28	29
14	41	29	34	28
15	36	33	17	23
16	28	19	22	11
17	15	22	7	13
18	21	18	13	19
19	14	7	11	4
20	7	9	7	4
21	8	4	1	1
22	4	6	4	1
23	4	3		2
24		1	1
25			1
26	1
27
28
29	1

Year	Q1 (Apr–Jun)	Q2 (Jul–Sep)	Q3 (Oct–Dec)	Q4 (Jan–Mar)
1	221	202	134	129
2	145	143	99	109
3	128	115	86	89
4	90	89	61	42
5	84	75	57	60
6	82	88	35	39
7	72	60	36	43
8	85	70	44	50
9	61	50	39	23
10	54	42	28	48
11	51	61	38	32
12	41	31	29	32
13	49	35	28	29
14	41	29	34	28
15	36	33	17	23
16	28	19	22	11
17	15	22	7	13
18	21	18	13	19
19	14	7	11	4
20	7	9	7	4
21	8	4	1	1
22	4	6	4	1
23	4	3		2
24		1	1
25			1
26	1
27
28
29	1

Year	Q1 (Apr–Jun)	Q2 (Jul–Sep)	Q3 (Oct–Dec)	Q4 (Jan–Mar)
1	221	202	134	129
2	145	143	99	109
3	128	115	86	89
4	90	89	61	42
5	84	75	57	60
6	82	88	35	39
7	72	60	36	43
8	85	70	44	50
9	61	50	39	23
10	54	42	28	48
11	51	61	38	32
12	41	31	29	32
13	49	35	28	29
14	41	29	34	28
15	36	33	17	23
16	28	19	22	11
17	15	22	7	13
18	21	18	13	19
19	14	7	11	4
20	7	9	7	4
21	8	4	1	1
22	4	6	4	1
23	4	3		2
24		1	1
25			1
26	1
27
28
29	1