Bob Feller had the highest K/9 in 1938, with 7.78 per nine innings.

Interpreted as:

highest k/9 with a minimum of 1 IP per team game by a player in 1938

	NAME	K/9	SEASON	TM	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Bob Feller B. Feller	7.78	1938	CLE	39	17	11	.607	36	4.08	240	20	2	1	277.2	225	126	136	13	208	7	3	1,248	5	6.74	1.15	0.42	19.2	16.7	1.56	.272	4.41	86	4.13	91	7.29	13
2	Bobo Newsom B. Newsom	6.17	1938	SLA	44	20	16	.556	40	5.08	226	31	0	1	329.2	334	186	205	30	192	5	3	1,475	3	5.24	1.18	0.82	15.3	13.0	1.60	.297	5.60	101	4.53	94	9.12	11.6
3	Lefty Mills L. Mills	5.73	1938	SLA	30	10	12	.455	27	5.31	134	15	1	0	210.1	216	124	139	16	116	8	2	962	5	4.96	1.16	0.68	13.9	12.1	1.58	.291	5.95	106	4.41	91	9.24	10.1
4	Lefty Grove L. Grove	5.44	1938	BSA	24	14	4	.778	21	3.08	99	12	1	1	163.2	169	56	65	8	52	1	3	706	3	2.86	1.90	0.44	14.0	7.4	1.35	.295	3.57	62	3.32	70	9.29	25.3
5	Carl Hubbell C. Hubbell	5.23	1938	NYG	24	13	10	.565	22	3.07	104	13	1	1	179.0	171	61	70	16	33	2	2	732	1	1.66	3.15	0.80	14.2	4.5	1.14	.269	3.52	81	3.51	88	8.60	9.2
6	Johnny Allen J. Allen	5.04	1938	CLE	30	14	8	.636	27	4.19	112	13	0	0	200.0	189	93	107	15	81	3	3	855	7	3.65	1.38	0.68	13.1	9.5	1.35	.270	4.82	88	4.04	89	8.51	11.4
7	Johnny Vander Meer J. Vander Meer	4.99	1938	CIN	32	15	10	.600	29	3.12	125	16	3	0	225.1	177	78	89	12	103	3	0	948	5	4.11	1.21	0.48	13.2	10.9	1.24	.234	3.55	85	3.92	102	7.07	-2.2
8	Lefty Gomez L. Gomez	4.86	1938	NYY	32	18	12	.600	32	3.35	129	20	4	0	239.0	239	89	110	7	99	1	0	1,034	5	3.73	1.30	0.26	12.5	9.6	1.41	.291	4.14	73	3.48	79	9.00	25.1
9	Red Ruffing R. Ruffing	4.62	1938	NYY	31	21	7	.750	31	3.31	127	22	3	0	247.1	246	91	104	16	82	0	0	1,043	1	2.98	1.55	0.58	12.2	7.9	1.33	.281	3.78	72	3.73	85	8.95	18.7
10	Bob Weiland B. Weiland	4.61	1938	SLN	35	16	11	.593	29	3.59	117	11	1	1	228.1	248	91	118	14	67	4	3	990	1	2.64	1.75	0.55	11.8	6.8	1.38	.297	4.65	93	3.63	90	9.78	10.8
11	Johnny Rigney J. Rigney	4.53	1938	CWS	38	9	9	.500	12	3.56	84	7	1	1	167.0	164	66	74	16	72	2	19	728	7	3.88	1.17	0.86	11.5	9.9	1.41	.267	3.99	74	4.49	98	8.84	1.9
12	Clay Bryant C. Bryant	4.49	1938	CHC	44	19	11	.633	30	3.10	135	17	3	2	270.1	235	93	105	6	125	1	10	1,146	5	4.16	1.08	0.20	11.8	10.9	1.33	.261	3.50	81	3.61	90	7.82	12.1
13	Jack Wilson J. Wilson	4.44	1938	BSA	37	15	15	.500	27	4.30	96	11	3	1	194.2	200	93	108	16	91	2	7	869	2	4.21	1.05	0.74	11.0	10.5	1.49	.277	4.99	87	4.44	94	9.25	6.7
14	Monte Pearson M. Pearson	4.37	1938	NYY	28	16	7	.696	27	3.97	98	17	1	0	202.0	198	89	107	12	113	0	1	888	9	5.03	0.87	0.53	11.0	12.7	1.54	.280	4.77	86	4.40	100	8.82	-0.4
15	Russ Bauers R. Bauers	4.33	1938	PIT	40	13	14	.481	34	3.07	117	12	2	3	243.0	207	83	102	7	99	6	6	1,008	6	3.67	1.18	0.26	11.6	9.8	1.26	.257	3.78	82	3.63	92	7.67	8
16	Bill McGee B. McGee	4.33	1938	SLN	47	7	12	.368	25	3.21	104	10	1	5	216.0	216	77	101	4	78	1	11	932	2	3.25	1.33	0.17	11.2	8.4	1.36	.285	4.21	83	3.30	81	9.00	18
17	Tex Carleton T. Carleton	4.29	1938	CHC	33	10	9	.526	24	5.42	80	9	0	0	167.2	213	101	118	11	74	8	6	785	12	3.97	1.08	0.59	10.2	9.4	1.71	.330	6.33	142	4.29	107	11.43	-5
18	Cy Blanton C. Blanton	4.17	1938	PIT	29	11	7	.611	26	3.70	80	10	1	0	172.2	190	71	84	13	46	2	0	729	2	2.40	1.74	0.68	11.0	6.3	1.37	.301	4.38	99	3.81	97	9.90	2.2
19	Vito Tamulis V. Tamulis	4.17	1938	TOT	41	12	9	.571	20	4.17	81	9	0	2	175.0	207	81	96	13	50	2	13	761	4	2.57	1.62	0.67	10.6	6.6	1.47	.315	4.94	103	3.86	93	10.65	6.1
20	Lon Warneke L. Warneke	4.07	1938	SLN	31	13	8	.619	26	3.97	89	12	4	0	197.0	199	87	102	14	64	2	3	855	6	2.92	1.39	0.64	10.4	7.5	1.34	.270	4.66	103	3.95	97	9.09	2.5
21	Al Hollingsworth A. Hollingsworth	4.02	1938	TOT	33	7	18	.280	25	4.36	93	12	1	0	208.1	220	101	117	6	89	0	4	912	8	3.84	1.04	0.26	10.2	9.8	1.48	.296	5.05	116	3.69	93	9.50	6
22	Monty Stratton M. Stratton	3.96	1938	CWS	26	15	9	.625	22	4.01	82	17	0	2	186.1	186	83	95	18	56	7	3	797	2	2.70	1.46	0.87	10.3	7.0	1.30	.265	4.59	84	4.31	94	8.98	5.9
23	Charlie Root C. Root	3.92	1938	CHC	44	8	7	.533	11	2.86	70	5	0	9	160.2	163	51	62	10	30	2	20	673	0	1.68	2.33	0.56	10.4	4.5	1.20	.273	3.47	75	3.46	86	9.13	9.9
24	Paul Derringer P. Derringer	3.87	1938	CIN	41	21	14	.600	37	2.93	132	26	4	3	307.0	315	100	110	20	49	0	4	1,263	1	1.44	2.69	0.59	10.5	3.9	1.19	.278	3.22	80	3.39	88	9.23	15.5
25	Mel Harder M. Harder	3.83	1938	CLE	38	17	10	.630	29	3.83	102	15	2	4	240.0	257	102	115	16	62	5	6	1,026	1	2.33	1.65	0.60	9.9	6.0	1.33	.287	4.31	81	3.78	83	9.64	20.7