Shane Bieber has the best K/9 in a season, with 14.20 per nine innings in 2020.

Interpreted as:

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

	NAME	K/9	SEASON	TM	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Shane Bieber S. Bieber	14.20	2020	CLE	12	8	1	.889	12	1.63	122	0	0	0	77.1	46	14	15	7	21	1	0	0	297	5	2.44	5.81	0.81	41.1	7.1	0.87	.267	1.75	37	2.06	46	5.35	20.5
2	Gerrit Cole G. Cole	13.82	2019	HOU	33	20	5	.800	33	2.50	326	0	0	0	212.1	142	59	66	29	48	3	0	0	817	4	2.03	6.79	1.23	39.9	5.9	0.89	.275	2.80	55	2.63	58	6.02	45
3	Jacob deGrom J. deGrom	13.76	2020	NYM	12	4	2	.667	12	2.38	104	0	0	0	68.0	47	18	21	7	18	0	0	0	268	4	2.38	5.78	0.93	38.8	6.7	0.96	.288	2.78	57	2.26	52	6.22	15.9
4	Spencer Strider S. Strider	13.55	2023	ATL	32	19	5	.792	32	3.86	281	0	0	0	186.2	146	80	85	22	58	9	0	1	763	6	2.80	4.84	1.06	36.8	7.6	1.09	.316	4.10	87	2.85	66	7.04	30.3
5	Randy Johnson R. Johnson	13.41	2001	ARI	35	21	6	.778	34	2.49	372	3	2	0	249.2	181	69	74	19	71	18	1	2	994	8	2.56	5.24	0.68	37.4	7.1	1.01	.315	2.67	55	2.12	48	6.52	63.9
6	Pedro Martinez P. Martinez	13.20	1999	BOS	31	23	4	.852	29	2.07	313	5	1	0	213.1	160	49	56	9	37	9	1	1	835	6	1.56	8.46	0.38	37.5	4.4	0.92	.323	2.36	42	1.38	30	6.75	79.4
7	Chris Sale C. Sale	12.93	2017	BOS	32	17	8	.680	32	2.90	308	1	0	0	214.1	165	69	73	24	43	8	0	0	851	3	1.81	7.16	1.01	36.2	5.1	0.97	.301	3.07	63	2.45	56	6.93	45.5
8	Max Scherzer M. Scherzer	12.69	2019	WSH	27	11	7	.611	27	2.92	243	0	0	0	172.1	144	56	59	18	33	7	0	2	693	0	1.72	7.36	0.94	35.1	4.8	1.03	.321	3.08	66	2.44	55	7.52	38.6
9	Corbin Burnes C. Burnes	12.61	2021	MIL	28	11	5	.688	28	2.43	234	0	0	0	167.0	123	45	47	7	34	6	0	0	657	5	1.83	6.88	0.38	35.6	5.2	0.94	.309	2.53	58	1.62	38	6.63	48.9
10	Kerry Wood K. Wood	12.58	1998	CHC	26	13	6	.684	26	3.40	233	1	1	0	166.2	117	63	69	14	85	11	0	1	699	6	4.59	2.74	0.76	33.3	12.2	1.21	.289	3.73	80	3.16	73	6.32	21.9
11	Randy Johnson R. Johnson	12.56	2000	ARI	35	19	7	.731	35	2.64	347	8	3	0	248.2	202	73	89	23	76	6	0	1	1,001	5	2.75	4.57	0.83	34.7	7.6	1.12	.326	3.22	56	2.53	53	7.31	61.1
12	Henry Porter H. Porter	12.53	1884	MIL	6	3	3	.500	6	3.00	71	6	1	0	51.0	32	17	25	1	9		0		200	6	1.59	7.89	0.18	35.5	4.5	0.80		4.41	23	1.27	11	5.65	24.1
13	Jose Fernandez J. Fernandez	12.49	2016	MIA	29	16	8	.667	29	2.86	253	0	0	0	182.1	149	58	63	13	55	6	0	6	737	9	2.71	4.60	0.64	34.3	7.5	1.12	.332	3.11	72	2.29	57	7.35	35.4
14	Gerrit Cole G. Cole	12.40	2018	HOU	32	15	5	.750	32	2.88	276	1	1	0	200.1	143	64	68	19	64	7	0	0	799	9	2.88	4.31	0.85	34.5	8.0	1.03	.286	3.05	70	2.70	65	6.42	32.7
15	Randy Johnson R. Johnson	12.35	1995	SEA	30	18	2	.900	30	2.48	294	6	3	0	214.1	159	59	65	12	65	6	0	1	866	5	2.73	4.52	0.50	33.9	7.5	1.05	.301	2.73	53	2.08	44	6.68	62
16	Trevor Bauer T. Bauer	12.33	2020	CIN	11	5	4	.556	11	1.73	100	2	2	0	73.0	41	14	17	9	17	3	0	1	278	3	2.10	5.88	1.11	36.0	6.1	0.79	.215	2.10	36	2.87	61	5.05	14.1
17	Max Scherzer M. Scherzer	12.30	2020	WSH	12	5	4	.556	12	3.74	92	1	0	0	67.1	70	28	30	10	23	1	0	1	295	6	3.07	4.00	1.34	31.2	7.8	1.38	.355	4.01	83	3.45	76	9.36	8
18	Randy Johnson R. Johnson	12.30	1997	SEA	30	20	4	.833	29	2.28	291	5	2	0	213.0	147	54	60	20	77	10	0	2	850	4	3.25	3.78	0.85	34.2	9.1	1.05	.281	2.54	50	2.82	62	6.21	41.3
19	Dylan Cease D. Cease	12.28	2021	CWS	32	13	7	.650	32	3.91	226	1	1	0	165.2	139	72	77	20	68	9	0	0	708	13	3.69	3.32	1.09	31.9	9.6	1.25	.309	4.18	90	3.40	76	7.55	18.9
20	Max Scherzer M. Scherzer	12.24	2018	WSH	33	18	7	.720	33	2.53	300	2	1	0	220.2	150	62	66	23	51	12	0	4	866	4	2.08	5.88	0.94	34.6	5.9	0.91	.265	2.69	62	2.65	64	6.12	36.1
21	Justin Verlander J. Verlander	12.20	2018	HOU	34	16	9	.640	34	2.52	290	1	1	0	214.0	156	60	63	28	37	8	0	0	833	5	1.56	7.84	1.18	34.8	4.4	0.90	.272	2.65	62	2.78	67	6.56	33
22	Robbie Ray R. Ray	12.13	2019	ARI	33	12	8	.600	33	4.34	235	0	0	0	174.1	150	84	91	30	84	5	0	5	747	7	4.34	2.80	1.55	31.5	11.2	1.34	.305	4.70	98	4.28	99	7.74	1
23	Dinelson Lamet D. Lamet	12.13	2020	SDP	12	3	1	.750	12	2.09	93	0	0	0	69.0	39	16	18	5	20	4	0	0	267	1	2.61	4.65	0.65	34.8	7.5	0.86	.234	2.35	49	2.47	56	5.09	15.1
24	Randy Johnson R. Johnson	12.12	1998	TOT	34	19	11	.633	34	3.28	329	10	6	0	244.1	203	89	102	23	86	14	0	1	1,014	7	3.17	3.83	0.85	32.4	8.5	1.18	.320	3.76	72	2.89	65	7.48	42.2
25	Aaron Nola A. Nola	12.11	2020	PHI	12	5	5	.500	12	3.28	96	2	1	0	71.1	54	26	31	9	23	2	0	2	289	1	2.90	4.17	1.14	33.2	8.0	1.08	.283	3.91	73	3.18	70	6.81	10.6