who has the most walks in history before the age of 27

Juan Soto has the most career bases on balls by a player younger than 27, with 896 bases on balls.

	NAME	BB	G	AB	R	H	2B	3B	HR	RBI	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Juan Soto J. Soto	896	1,096	3,857	775	1,086	199	16	244	697	19	833	95	27	4,801	2,049	459	3	26	80	101	.282	.417	.531	.948
2	Mickey Mantle M. Mantle	797	1,102	3,937	889	1,238	185	50	249	766	7	778	76	24	4,768	2,270	484	11	16	48	37	.314	.429	.577	1.006
3	Eddie Yost E. Yost	742	1,017	3,762	610	978	193	37	55	327	38	406	35	12	4,604	1,410	285	62			75	.260	.387	.375	.762
4	Mel Ott M. Ott	707	1,288	4,542	912	1,440	257	47	242	963	24	359	45		5,332	2,517	546	59				.317	.412	.554	.966
5	Bryce Harper B. Harper	684	1,084	3,879	708	1,071	219	19	219	635	29	1,012	90	34	4,639	1,985	457	9	38	81	76	.276	.385	.512	.897
6	Mike Trout M. Trout	670	1,034	3,771	774	1,155	221	43	231	629	62	971	186	34	4,546	2,155	495	0	43	81	52	.306	.415	.571	.987
7	Jimmie Foxx J. Foxx	668	1,109	3,862	857	1,307	224	72	266	961	7	545	42		4,592	2,473	562	55				.338	.437	.640	1.077
8	Eddie Mathews E. Mathews	645	1,029	3,752	703	1,039	165	34	253	663	9	609	34	16	4,456	2,031	452	23	27	47	50	.277	.382	.541	.923
9	Rickey Henderson R. Henderson	619	934	3,463	732	1,022	157	34	75	343	23	481	573	148	4,142	1,472	266	16	21	22	48	.295	.403	.425	.828
10	Donie Bush D. Bush	599	922	3,345	644	842	100	35	7		19		259		4,121	1,033	142	158				.252	.368	.309	.677
11	Adam Dunn A. Dunn	574	821	2,832	519	695	151	6	198	466	46	927	48	16	3,466	1,452	355	2	12	60	38	.245	.380	.513	.892
12	Harlond Clift H. Clift	571	842	3,090	637	891	176	40	119	502	29	388	40		3,719	1,504	335	29			5	.288	.404	.487	.891
13	Arky Vaughan A. Vaughan	571	997	3,705	660	1,231	201	83	65	570	28	170	54		4,362	1,793	349	58				.332	.425	.484	.909
14	Frank Thomas F. Thomas	555	669	2,358	479	770	164	8	148	505	14	384	14	11	2,963	1,394	320	0	36	62	70	.327	.452	.591	1.043
15	Rusty Staub R. Staub	545	1,151	4,024	484	1,114	205	24	116	543	33	465	23	21	4,678	1,715	345	42	34	97	93	.277	.365	.426	.791
16	Elbie Fletcher E. Fletcher	532	922	3,233	481	887	151	41	54	407	27	319	24		3,823	1,282	246	31			33	.274	.381	.397	.778
17	Lou Gehrig L. Gehrig	520	819	2,940	677	993	221	74	164	706	17	372	36		3,564	1,854	459	87				.338	.440	.631	1.071
18	Ken Griffey Jr. K. Griffey Jr.	504	1,057	3,985	695	1,204	227	21	238	725	25	634	108	44	4,558	2,187	486	6	38	119	75	.302	.381	.549	.930
19	Charlie Keller C. Keller	498	661	2,385	482	701	101	48	117	478	3	292	41		2,903	1,249	266	17			30	.294	.416	.524	.940
20	Joe Morgan J. Morgan	495	719	2,638	440	701	105	47	46	217	10	311	152	50	3,180	1,038	198	24	13	12	22	.266	.382	.393	.776
21	Albert Pujols A. Pujols	493	933	3,489	748	1,159	260	12	250	758	48	394	36	17	4,062	2,193	522	1	31	98	114	.332	.419	.629	1.047
22	Ted Williams T. Williams	493	586	2,104	541	749	154	33	127	515	12	196	11		2,613	1,350	314	4			45	.356	.481	.642	1.122
23	Babe Ruth B. Ruth	484	686	2,111	537	718	162	55	162	527	16	346	44		2,641	1,476	379	30				.340	.466	.699	1.166
24	Ron Santo R. Santo	479	1,053	3,921	526	1,108	189	43	167	618	19	590	22	21	4,465	1,884	399	8	38	43	107	.283	.360	.480	.841
25	Al Kaline A. Kaline	474	1,204	4,505	714	1,390	226	45	159	694	23	378	84	39	5,070	2,183	430	28	40	46	123	.309	.374	.485	.859