highest obp in american league with a minimum 500 pa under age-by by by 20 season

Ted Williams has the highest on-base percentage in the AL with 500+ plate appearances in a season, with an on-base percentage of .553 in 1941.

Interpreted as:

highest obp in american league with a minimum 500 pa under age-by a player by by 20 season

	NAME	OBP	PA	AGE	SEASON	TM	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	TB	XBH	SH	SF	IBB	GIDP	AVG	SLG	OPS	WRC	WRAA	WOBA	WRC+	BRAA
1	Ted Williams T. Williams	.553	606	22	1941	BSA	143	456	135	185	33	3	37	120	147	3	27	2	4	335	73	0			10	.406	.735	1.287	179	108.8	.568	221	96.9
2	Babe Ruth B. Ruth	.545	699	28	1923	NYY	152	522	151	205	45	13	41	130	170	4	93	17	21	399	99	3				.393	.764	1.309	211	124.7	.571	230	120.4
3	Babe Ruth B. Ruth	.532	616	25	1920	NYY	142	458	158	172	36	9	54	135	150	3	80	14	14	388	99	5				.376	.847	1.379	191	120.9	.597	237	110.5
4	Ted Williams T. Williams	.526	546	38	1957	BOS	132	420	96	163	28	1	38	87	119	5	43	0	1	307	67	0	2	33	11	.388	.731	1.257	148	87.3	.524	223	79
5	Babe Ruth B. Ruth	.516	652	31	1926	NYY	152	495	139	184	30	5	47	153	144	3	76	11	9	365	82	10				.372	.737	1.253	184	105.6	.551	216	100.6
6	Ted Williams T. Williams	.513	526	35	1954	BOS	117	386	93	133	23	1	29	89	136	1	32	0	0	245	53	0	3		10	.345	.635	1.148	131	71.1	.507	207	65.5
7	Babe Ruth B. Ruth	.513	681	29	1924	NYY	153	529	143	200	39	7	46	124	142	4	81	9	13	391	92	6				.378	.739	1.252	193	109.2	.549	210	102
8	Babe Ruth B. Ruth	.512	693	26	1921	NYY	152	540	177	204	44	16	59	168	145	4	81	17	13	457	119	4				.378	.846	1.359	214	127.8	.575	224	118.7
9	Mickey Mantle M. Mantle	.512	623	25	1957	NYY	144	474	121	173	28	6	34	94	146	0	75	16	3	315	68	0	3	23	5	.365	.665	1.177	157	87.1	.498	217	86
10	Ted Williams T. Williams	.499	671	23	1942	BSA	150	522	141	186	34	5	36	137	145	4	51	3	2	338	75	0			12	.356	.648	1.147	168	96.2	.524	209	86.5
11	Ted Williams T. Williams	.499	693	28	1947	BSA	156	528	125	181	40	9	32	114	162	2	47	0	1	335	81	1			10	.343	.634	1.133	170	91.3	.508	207	86.2
12	Ted Williams T. Williams	.497	672	27	1946	BSA	150	514	142	176	37	8	38	123	156	2	44	0	0	343	83	0			12	.342	.667	1.164	166	95.8	.525	214	87.5
13	Ted Williams T. Williams	.497	638	29	1948	BSA	137	509	124	188	44	3	25	127	126	3	41	4	0	313	72	0			10	.369	.615	1.112	156	81	.504	184	68.8
14	Babe Ruth B. Ruth	.495	663	36	1931	NYY	145	534	149	199	31	3	46	162	128	1	51	5	4	374	80	0				.373	.700	1.195	181	98.6	.525	206	95.1
15	Babe Ruth B. Ruth	.493	676	35	1930	NYY	145	518	150	186	28	9	49	153	136	1	61	10	10	379	86	21				.359	.732	1.225	192	97	.517	204	100.6
16	Ted Williams T. Williams	.490	730	30	1949	BSA	155	566	150	194	39	3	43	159	162	2	48	1	1	368	85	0			22	.343	.650	1.141	182	95.5	.511	187	82.2
17	Babe Ruth B. Ruth	.489	589	37	1932	NYY	133	457	120	156	13	5	41	137	130	2	62	2	2	302	59	0				.341	.661	1.150	153	79.1	.501	192	75.3
18	Frank Thomas F. Thomas	.487	517	26	1994	CWS	113	399	106	141	34	1	38	101	109	2	61	2	3	291	73	0	7	12	15	.353	.729	1.217	138	72.3	.499	205	71.9
19	Norm Cash N. Cash	.487	672	26	1961	DET	159	535	119	193	22	8	41	132	124	9	85	11	5	354	71	2	2	19	16	.361	.662	1.148	168	88.3	.488	194	79.5
20	Ty Cobb T. Cobb	.486	700	28	1915	DET	156	563	144	208	31	13	3	99	118	10	43	96	38	274	47	9				.369	.487	.973	143	71	.467	184	64.2
21	Mickey Mantle M. Mantle	.486	502	30	1962	NYY	123	377	96	121	15	1	30	89	122	1	78	9	0	228	46	0	2	9	4	.321	.605	1.091	118	59.5	.472	192	57.6
22	Babe Ruth B. Ruth	.486	691	32	1927	NYY	151	540	158	192	29	8	60	165	137	0	89	7	6	417	97	14				.356	.772	1.258	195	109.9	.545	212	104.8
23	Tristram Speaker T. Speaker	.483	674	32	1920	CLE	150	552	137	214	50	11	8	107	97	5	13	10	13	310	69	20				.388	.562	1.045	152	74.9	.483	170	62
24	Harry Heilmann H. Heilmann	.481	626	28	1923	DET	144	524	121	211	44	11	18	115	74	5	40	9	7	331	73	23				.403	.632	1.113	155	78	.503	189	73.3
25	Ted Williams T. Williams	.479	503	37	1956	BOS	136	400	71	138	28	2	24	82	102	1	39	0	0	242	54	0	0	11	13	.345	.605	1.084	116	57.5	.470	175	47.8