The Chicago White Sox had the highest K/9 by a team in 2021, with 10.18 per nine innings.

	TEAM	K/9	SEASON	G	W%	W	L	GS	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	IBB	TBF	WP	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	White Sox	10.18	2021	162	.574	93	69	162	3.73	1,588	4	3	43	1403.1	1,205	581	636	182	485	51	16	5,861	84	3.11	3.27	1.17	27.1	8.3	1.20	.288	4.08	7.73
2	Brewers	10.14	2021	162	.586	95	67	162	3.50	1,618	2	1	44	1436.0	1,156	558	623	168	537	77	19	5,990	60	3.37	3.01	1.05	27.0	9.0	1.18	.275	3.90	7.25
3	Dodgers	9.91	2021	162	.654	106	56	162	3.01	1,599	1	0	56	1452.0	1,107	486	561	161	486	63	43	5,948	52	3.01	3.29	1.00	26.9	8.2	1.10	.260	3.48	6.86
4	Yankees	9.84	2021	162	.568	92	70	162	3.74	1,569	3	2	47	1435.1	1,243	596	669	196	492	56	10	5,999	85	3.08	3.19	1.23	26.2	8.2	1.21	.284	4.19	7.79
5	Red Sox	9.68	2021	162	.568	92	70	162	4.26	1,527	0	0	49	1419.0	1,409	671	749	176	546	79	31	6,147	63	3.46	2.80	1.12	24.8	8.9	1.38	.323	4.75	8.94
6	Reds	9.56	2021	162	.512	83	79	162	4.40	1,524	1	1	41	1434.1	1,330	702	760	206	617	64	30	6,199	62	3.87	2.47	1.29	24.6	10.0	1.36	.297	4.77	8.35
7	Padres	9.55	2021	162	.488	79	83	162	4.10	1,517	2	2	43	1430.0	1,277	651	708	205	516	87	33	6,056	57	3.25	2.94	1.29	25.0	8.5	1.25	.287	4.46	8.04
8	Mets	9.48	2021	162	.475	77	85	162	3.90	1,453	2	1	41	1379.1	1,221	597	668	190	475	70	21	5,785	53	3.10	3.06	1.24	25.1	8.2	1.23	.287	4.36	7.97
9	Blue Jays	9.40	2021	162	.562	91	71	162	3.91	1,468	1	1	34	1405.1	1,257	610	663	209	473	75	10	5,916	54	3.03	3.10	1.34	24.8	8.0	1.23	.284	4.25	8.05
10	Phillies	9.39	2021	162	.506	82	80	162	4.39	1,480	5	4	36	1418.2	1,321	692	745	200	509	75	37	6,055	49	3.23	2.91	1.27	24.4	8.4	1.29	.296	4.73	8.38
11	Angels	9.20	2021	162	.475	77	85	162	4.69	1,453	1	0	39	1421.2	1,373	741	804	188	592	76	18	6,196	56	3.75	2.45	1.19	23.5	9.6	1.38	.305	5.09	8.69
12	Rays	9.14	2021	162	.617	100	62	162	3.67	1,478	1	0	42	1455.2	1,264	593	651	184	436	55	27	5,998	64	2.70	3.39	1.14	24.6	7.3	1.17	.281	4.02	7.81
13	Astros	9.07	2021	162	.586	95	67	162	3.78	1,456	2	0	34	1445.0	1,231	607	658	187	549	70	12	6,060	72	3.42	2.65	1.16	24.0	9.1	1.23	.275	4.10	7.67
14	Braves	9.04	2021	161	.547	88	73	161	3.88	1,417	2	2	40	1410.2	1,237	608	656	183	516	66	34	5,944	73	3.29	2.75	1.17	23.8	8.7	1.24	.280	4.19	7.89
15	Indians	8.89	2021	162	.494	80	82	162	4.34	1,391	0	0	39	1408.0	1,281	679	727	216	522	59	12	5,968	52	3.34	2.66	1.38	23.3	8.7	1.28	.282	4.65	8.19
16	Giants	8.81	2021	162	.660	107	55	162	3.24	1,425	2	2	56	1455.0	1,254	524	594	151	416	63	20	6,002	44	2.57	3.43	0.93	23.7	6.9	1.15	.279	3.67	7.76
17	Marlins	8.78	2021	162	.414	67	95	162	3.96	1,381	1	0	33	1415.0	1,282	622	701	162	529	88	43	6,027	58	3.36	2.61	1.03	22.9	8.8	1.28	.290	4.46	8.15
18	Nationals	8.69	2021	162	.401	65	97	162	4.80	1,346	1	0	36	1394.1	1,364	743	820	247	548	71	46	6,073	43	3.54	2.46	1.59	22.2	9.0	1.37	.289	5.29	8.80
19	Cubs	8.65	2021	162	.438	71	91	162	4.87	1,358	1	0	40	1412.2	1,386	765	839	235	596	98	25	6,202	60	3.80	2.28	1.50	21.9	9.6	1.40	.294	5.35	8.83
20	Royals	8.53	2021	162	.457	74	88	162	4.64	1,344	1	0	37	1417.1	1,375	731	788	189	591	62	16	6,127	86	3.75	2.27	1.20	21.9	9.6	1.39	.301	5.00	8.73
21	Pirates	8.46	2021	162	.377	61	101	162	5.08	1,312	0	0	25	1396.1	1,400	788	833	213	606	78	26	6,140	55	3.91	2.17	1.37	21.4	9.9	1.44	.302	5.37	9.02
22	Athletics	8.37	2021	162	.531	86	76	162	4.02	1,332	3	3	39	1433.0	1,362	640	687	191	439	64	11	6,060	63	2.76	3.03	1.20	22.0	7.2	1.26	.290	4.31	8.55
23	Twins	8.35	2021	162	.451	73	89	162	4.83	1,317	1	0	42	1419.1	1,392	762	834	239	484	62	13	6,080	48	3.07	2.72	1.52	21.7	8.0	1.32	.290	5.29	8.83
24	Mariners	8.30	2021	162	.556	90	72	162	4.30	1,328	1	0	51	1440.1	1,356	688	748	197	485	69	23	6,106	58	3.03	2.74	1.23	21.7	7.9	1.28	.288	4.67	8.47
25	Rockies	8.18	2021	161	.460	74	87	161	4.82	1,269	3	1	33	1397.0	1,397	748	796	196	539	63	19	6,044	67	3.47	2.35	1.26	21.0	8.9	1.39	.302	5.13	9.00