Mel Ott has the most career bases on balls by a player younger than 22, with 285 walks.

Interpreted as:

most walks before turning 22 years old by a player

	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	Mel Ott M. Ott	285	539	1,724	359	570	106	14	86	372	10	127	21		2,064	962	206	45				.331	.428	.558	.986
2	Juan Soto J. Soto	228	313	1,110	226	328	71	6	69	217	4	259	23	5	1,349	618	146	1	6	25	21	.295	.415	.557	.972
3	Mickey Mantle M. Mantle	197	365	1,351	260	398	72	15	57	244	0	275	20	12	1,552	671	144	4			10	.295	.384	.497	.881
4	Ted Williams T. Williams	186	264	1,007	243	337	82	21	49	233	5	107	5		1,202	608	152	4			19	.335	.441	.604	1.045
5	Jimmie Foxx J. Foxx	179	364	1,088	241	372	61	25	49	223	4	131	15		1,302	630	135	31				.342	.437	.579	1.016
6	Ken Griffey Jr. K. Griffey Jr.	178	436	1,600	228	478	93	8	60	241	5	246	50	24	1,805	767	161	5	17	41	26	.299	.367	.479	.847
7	Al Kaline A. Kaline	175	473	1,737	269	540	74	21	59	275	7	161	23	14	1,939	833	154	8	12	16	48	.311	.374	.480	.853
8	Eddie Mathews E. Mathews	158	302	1,107	190	303	54	13	72	193	3	200	7	7	1,274	599	139	6			16	.274	.366	.541	.907
9	Bryce Harper B. Harper	155	357	1,309	210	356	60	14	55	149	8	318	31	12	1,489	609	129	9	8	8	18	.272	.351	.465	.816
10	Rickey Henderson R. Henderson	151	247	942	160	275	35	7	10	79	7	93	133	37	1,120	354	52	14	6	7	10	.292	.392	.376	.767
11	Butch Wynegar B. Wynegar	147	293	1,066	134	278	43	5	20	148	4	124	2	3	1,239	391	68	14	8	12	25	.261	.350	.367	.717
12	Mike Trout M. Trout	143	290	1,114	228	352	65	16	54	167	15	254	77	9	1,286	611	135	0	14	10	15	.316	.397	.548	.945
13	Buddy Lewis B. Lewis	139	407	1,739	287	520	74	26	25	214	7	119	29		1,907	721	125	22				.299	.353	.415	.768
14	Tony Conigliaro T. Conigliaro	137	399	1,483	228	405	68	14	84	227	15	306	6	8	1,657	753	166	12	10	15	26	.273	.339	.508	.846
15	Eddie Yost E. Yost	133	275	1,022	131	244	50	14	2	65	6	115	9		1,180	328	66	19			24	.239	.330	.321	.651
16	Rusty Staub R. Staub	132	370	1,215	112	283	47	7	28	143	10	146	4	1	1,375	428	82	7	11	17	35	.233	.311	.352	.663
17	Adrian Beltre A. Beltre	131	367	1,243	173	338	66	7	42	174	11	222	33	13	1,403	544	115	9	9	14	21	.272	.344	.438	.782
18	Ed Kranepool E. Kranepool	130	507	1,688	164	417	71	12	38	169	7	238	6	10	1,848	626	121	5	18	18	38	.247	.301	.371	.671
19	Jason Heyward J. Heyward	128	230	813	122	209	44	6	30	102	14	191	16	8	957	355	80	0	2	4	18	.257	.367	.437	.803
20	Robin Yount R. Yount	123	556	2,095	238	560	94	14	17	175	4	263	51	28	2,272	733	125	34	16	7	33	.267	.307	.350	.657
21	Ronald Acuña Jr. R. Acuña Jr.	121	267	1,059	205	302	48	6	67	165	15	311	53	14	1,199	563	121	0	4	6	12	.285	.365	.532	.897
22	Whitey Witt W. Witt	118	265	992	121	243	29	18	2		2	116	30		1,130	314	49	18				.245	.326	.317	.643
23	Sibby Sisti S. Sisti	116	409	1,476	196	363	56	12	12	116	9	212	18		1,627	479	80	26			26	.246	.305	.325	.629
24	Andruw Jones A. Jones	115	357	1,136	171	284	59	11	55	184	9	275	51	16	1,274	530	125	6	8	10	23	.250	.322	.467	.788
25	Bobby Doerr B. Doerr	114	327	1,181	167	347	59	10	19	167	2	96	8		1,333	483	88	36			17	.294	.357	.409	.766