Bump Hadley had the highest K/9 in 1931, with 6.21 per nine innings.

Interpreted as:

pitchers with highest k/9 with a minimum of 1 IP per team game in 1931

	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	Bump Hadley B. Hadley	6.21	1931	WSH	55	11	10	.524	11	3.06	124	2	1	7	179.2	145	61	81	4	92	1	28	768	4	4.61	1.35	0.20	16.1	12.0	1.32	.258	4.06	71	3.57	86	7.26	11.5
2	Dazzy Vance D. Vance	6.17	1931	BKN	30	11	13	.458	29	3.38	150	12	2	0	218.2	221	82	99	12	53	0	1	918	1	2.18	2.83	0.49	16.3	5.8	1.25	.297	4.07	89	3.18	81	9.10	18
3	Bill Hallahan B. Hallahan	5.75	1931	SLN	37	19	9	.679	30	3.29	159	16	3	3	248.2	242	91	102	10	112	1	6	1,061	11	4.05	1.42	0.36	15.0	10.6	1.42	.298	3.69	84	3.72	92	8.76	9.1
4	Paul Derringer P. Derringer	5.70	1931	SLN	35	18	8	.692	23	3.36	134	15	4	2	211.2	225	79	88	9	65	4	10	901	6	2.76	2.06	0.38	14.9	7.2	1.37	.313	3.74	86	3.38	84	9.57	15.7
5	Carl Hubbell C. Hubbell	5.63	1931	NYG	36	14	12	.538	30	2.65	155	21	4	3	248.0	211	73	88	14	67	4	5	1,010	3	2.43	2.31	0.51	15.3	6.6	1.12	.256	3.19	71	3.46	89	7.66	11.5
6	Lefty Gomez L. Gomez	5.56	1931	NYY	40	21	9	.700	26	2.67	150	17	1	3	243.0	206	72	88	7	85	4	10	1,013	1	3.15	1.76	0.26	14.8	8.4	1.20	.259	3.26	64	3.35	83	7.63	18.2
7	Tommy Bridges T. Bridges	5.46	1931	DET	35	8	16	.333	23	4.99	105	8	2	0	173.0	182	96	120	13	108	0	8	809	9	5.62	0.97	0.68	13.0	13.3	1.68	.290	6.24	111	4.75	109	9.47	-6.7
8	Lefty Grove L. Grove	5.46	1931	PHA	41	31	4	.886	30	2.06	175	27	4	5	288.2	249	66	84	10	62	1	10	1,160	2	1.93	2.82	0.31	15.1	5.3	1.08	.262	2.62	47	3.01	70	7.76	40.8
9	Red Ruffing R. Ruffing	5.01	1931	NYY	37	16	14	.533	30	4.41	132	19	1	2	237.0	240	116	130	11	87	6	5	1,042	1	3.30	1.52	0.42	12.7	8.3	1.38	.284	4.94	106	3.78	94	9.11	5.8
10	Hank Johnson H. Johnson	4.86	1931	NYY	40	13	8	.619	23	4.72	106	8	0	4	196.1	176	103	114	13	102	1	11	864	5	4.68	1.04	0.60	12.3	11.8	1.42	.254	5.23	113	4.47	111	8.07	-11
11	George Earnshaw G. Earnshaw	4.86	1931	PHA	43	21	7	.750	30	3.67	152	23	3	6	281.2	255	115	130	16	75	3	11	1,174	5	2.40	2.03	0.51	12.9	6.4	1.17	.258	4.15	83	3.60	84	8.15	21.3
12	Charlie Root C. Root	4.70	1931	CHC	39	17	14	.548	31	3.48	131	19	3	2	251.0	240	97	109	7	71	7	6	1,043	1	2.55	1.85	0.25	12.6	6.8	1.24	.282	3.91	90	3.36	84	8.61	17.9
13	Bill Walker B. Walker	4.55	1931	NYG	37	16	9	.640	28	2.26	121	19	6	5	239.1	212	60	78	6	64	3	7	991	2	2.41	1.89	0.23	12.2	6.5	1.15	.258	2.93	60	3.27	84	7.97	16.3
14	Carl Fischer C. Fischer	4.52	1931	WSH	46	13	9	.591	23	4.38	96	7	0	3	191.0	207	93	98	12	80	2	13	847	4	3.77	1.20	0.57	11.3	9.4	1.50	.297	4.62	102	4.21	101	9.75	-1.6
15	Pat Malone P. Malone	4.41	1931	CHC	36	16	9	.640	30	3.90	112	12	2	0	228.1	229	99	115	9	88	4	4	989	5	3.47	1.27	0.35	11.3	8.9	1.39	.284	4.53	101	3.85	96	9.03	3.8
16	Ray Benge R. Benge	4.26	1931	PHN	38	14	18	.438	31	3.17	117	16	2	2	247.0	251	87	107	12	61	5	7	1,044	2	2.22	1.92	0.44	11.2	5.8	1.26	.282	3.90	73	3.60	80	9.15	23.9
17	Ed Brandt E. Brandt	4.03	1931	BSN	33	18	11	.621	29	2.92	112	23	3	2	250.0	228	81	94	11	77	4	4	1,035	3	2.77	1.45	0.40	10.8	7.4	1.22	.261	3.38	79	3.76	98	8.21	1.5
18	Wes Ferrell W. Ferrell	4.01	1931	CLE	40	22	12	.647	35	3.75	123	27	2	3	276.1	276	115	134	9	130	3	4	1,227	3	4.23	0.95	0.29	10.0	10.6	1.47	.278	4.36	81	4.09	92	8.99	11.7
19	Syl Johnson S. Johnson	3.97	1931	SLN	32	11	9	.550	24	3.00	82	12	2	2	186.0	186	62	73	9	29	2	6	766	3	1.40	2.83	0.44	10.7	3.8	1.16	.275	3.53	77	3.36	83	9.00	14.1
20	Watty Clark W. Clark	3.70	1931	BKN	34	14	10	.583	28	3.20	96	16	3	1	233.1	243	83	86	4	52	1	2	981	3	2.01	1.85	0.15	9.8	5.3	1.26	.289	3.32	85	3.19	81	9.37	18.9
21	Vic Sorrell V. Sorrell	3.64	1931	DET	35	13	14	.481	32	4.15	99	19	1	1	245.0	267	113	131	8	114	1	3	1,098	2	4.19	0.87	0.29	9.0	10.4	1.56	.296	4.81	92	4.14	95	9.81	6.7
22	Firpo Marberry F. Marberry	3.62	1931	WSH	45	16	4	.800	25	3.45	88	11	1	8	219.0	211	84	92	13	63	3	14	913	3	2.59	1.40	0.53	9.6	6.9	1.25	.265	3.78	80	3.98	96	8.67	3.8
23	Jumbo Elliott J. Elliott	3.58	1931	PHN	52	19	14	.576	30	4.27	99	12	2	5	249.0	288	118	138	15	83	4	16	1,098	1	3.00	1.19	0.54	9.0	7.6	1.49	.304	4.99	99	4.15	93	10.41	10.5
24	Art Herring A. Herring	3.49	1931	DET	35	7	13	.350	16	4.31	64	9	0	1	165.0	186	79	95	8	67	8	12	744	0	3.65	0.96	0.44	8.6	9.0	1.53	.298	5.18	96	4.33	99	10.15	1
25	Rube Walberg R. Walberg	3.28	1931	PHA	44	20	12	.625	35	3.74	106	19	1	4	291.0	298	121	133	16	109	0	8	1,248	3	3.37	0.97	0.49	8.5	8.7	1.40	.277	4.11	85	4.22	99	9.22	2.1