Spencer Strider has the best career K/9 when starting 50+ games, with 12.38 per nine innings.

Interpreted as:

most k/9 by a player last 50+ starts

	NAME	K/9	GS	G	W	L	W%	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	Spencer Strider S. Strider	12.38	77	90	38	24	.613	3.74	626	0	0	0	455.0	368	189	198	52	160	20	3	2	1,881	13	3.16	3.91	1.03	33.3	8.5	1.16	.309	3.92	87	3.09	75	7.28	52.1
2	Garrett Crochet G. Crochet	11.64	64	136	27	24	.529	2.95	549	1	1	0	424.1	345	139	151	45	119	11	18	2	1,725	15	2.52	4.61	0.95	31.8	6.9	1.09	.300	3.20	70	2.86	67	7.32	64.7
3	Dinelson Lamet D. Lamet	11.60	60	121	17	24	.415	4.63	474	0	0	1	367.2	311	189	206	53	170	22	12	3	1,586	31	4.16	2.79	1.30	29.9	10.7	1.31	.298	5.04	108	4.03	93	7.61	12
4	Shohei Ohtani S. Ohtani	11.41	100	100	39	20	.661	3.00	670	1	1	0	528.2	388	176	184	56	182	24	0	2	2,139	52	3.10	3.68	0.95	31.3	8.5	1.08	.275	3.13	71	3.17	74	6.61	62.1
5	Tyler Glasnow T. Glasnow	11.36	128	167	43	36	.544	3.74	952	0	0	0	754.0	575	313	333	94	290	13	9	5	3,085	63	3.46	3.28	1.12	30.9	9.4	1.15	.277	3.97	91	3.47	83	6.86	59.4
6	Jose Fernandez J. Fernandez	11.25	76	76	38	17	.691	2.58	589	0	0	0	471.1	357	135	150	31	140	13	0	12	1,888	16	2.67	4.21	0.59	31.2	7.4	1.05	.292	2.86	68	2.43	64	6.82	73
7	Hunter Greene H. Greene	11.20	91	91	25	29	.463	3.65	617	2	2	0	495.2	386	201	211	70	179	39	0	0	2,060	21	3.25	3.45	1.27	30.0	8.7	1.14	.274	3.83	82	3.83	88	7.01	29.1
8	Blake Snell B. Snell	11.19	222	222	81	62	.566	3.15	1,440	1	1	0	1158.0	891	405	440	111	521	11	0	6	4,791	86	4.05	2.76	0.86	30.1	10.9	1.22	.288	3.42	77	3.31	79	6.92	111.7
9	Freddy Peralta F. Peralta	11.15	162	211	70	42	.625	3.59	1,153	1	0	1	931.0	694	371	392	118	360	48	6	3	3,853	31	3.48	3.20	1.14	29.9	9.3	1.13	.265	3.79	85	3.66	87	6.71	59.2
10	Chris Sale C. Sale	11.14	312	393	145	88	.622	3.01	2,579	16	3	12	2084.0	1,692	697	750	213	487	130	25	15	8,389	48	2.10	5.30	0.92	30.7	5.8	1.05	.297	3.24	70	2.87	68	7.31	303.3
11	Dylan Cease D. Cease	10.91	188	188	65	58	.528	3.88	1,231	3	3	0	1015.1	854	438	482	121	430	35	0	9	4,304	55	3.81	2.86	1.07	28.6	10.0	1.26	.295	4.27	93	3.66	85	7.57	67.6
12	Paul Skenes P. Skenes	10.83	55	55	21	13	.618	1.96	386	1	0	0	320.2	230	70	76	21	74	12	0	0	1,247	4	2.08	5.22	0.59	31.0	5.9	0.95	.277	2.13	46	2.39	58	6.46	61
13	Robbie Ray R. Ray	10.83	261	265	88	81	.521	3.94	1,734	2	1	0	1441.0	1,250	631	674	216	608	51	1	19	6,097	60	3.80	2.85	1.35	28.4	10.0	1.29	.296	4.21	94	4.06	99	7.81	5.1
14	Jacob deGrom J. deGrom	10.82	248	248	96	65	.596	2.57	1,851	4	2	0	1539.2	1,173	440	477	146	345	25	0	13	6,045	30	2.02	5.37	0.85	30.6	5.7	0.99	.279	2.79	66	2.70	66	6.86	239.4
15	Cole Ragans C. Ragans	10.80	66	83	21	20	.512	3.66	461	1	0	0	384.0	312	156	168	35	144	10	1	2	1,585	22	3.38	3.20	0.82	29.1	9.1	1.19	.296	3.94	86	3.16	76	7.31	42.6
16	Andrew Miller A. Miller	10.63	66	612	55	55	.500	4.03	979	0	0	63	829.0	732	371	413	80	383	61	147	14	3,619	44	4.16	2.56	0.87	27.1	10.6	1.34	.308	4.48	95	3.63	87	7.95	49.8
17	Randy Johnson R. Johnson	10.61	603	618	303	166	.646	3.29	4,875	100	37	2	4135.1	3,346	1,513	1,703	411	1,497	190	7	37	17,067	109	3.26	3.26	0.89	28.6	8.8	1.17	.291	3.71	75	3.18	73	7.28	554.3
18	Max Scherzer M. Scherzer	10.60	474	483	220	117	.653	3.22	3,489	12	5	0	2963.0	2,433	1,059	1,132	354	779	114	2	20	11,987	80	2.37	4.48	1.08	29.1	6.5	1.08	.287	3.44	77	3.23	78	7.39	302.5
19	Stephen Strasburg S. Strasburg	10.55	247	247	113	62	.646	3.24	1,723	2	2	0	1470.0	1,217	530	582	149	394	53	0	20	5,962	44	2.41	4.37	0.91	28.9	6.6	1.10	.293	3.56	80	3.01	75	7.45	165.9
20	Brandon Woodruff B. Woodruff	10.52	127	142	53	28	.654	3.10	871	2	1	1	745.0	580	257	269	84	190	32	4	1	2,984	8	2.30	4.58	1.01	29.2	6.4	1.03	.274	3.25	73	3.18	75	7.01	89
21	Yu Darvish Y. Darvish	10.50	297	297	115	93	.553	3.65	2,075	2	1	0	1778.0	1,460	721	756	231	563	83	0	8	7,305	83	2.85	3.69	1.17	28.4	7.7	1.14	.282	3.83	87	3.58	85	7.39	120
22	Danny Salazar D. Salazar	10.47	105	109	38	34	.528	3.82	688	1	1	0	591.1	536	251	268	75	213	15	3	8	2,482	24	3.24	3.23	1.14	27.7	8.6	1.27	.309	4.08	91	3.61	88	8.16	33.1
23	Tarik Skubal T. Skubal	10.44	134	137	54	37	.593	3.08	889	1	1	0	766.2	614	262	287	90	172	26	1	0	3,056	11	2.02	5.17	1.06	29.1	5.6	1.03	.279	3.37	75	3.14	76	7.21	84
24	Ryne Stanek R. Stanek	10.43	56	466	21	23	.477	3.85	531	0	0	14	458.1	371	196	218	61	232	10	98	14	1,956	34	4.56	2.29	1.20	27.1	11.9	1.32	.276	4.28	93	4.16	100	7.29	-1.5
25	Mark Prior M. Prior	10.37	106	106	42	29	.592	3.51	757	5	1	0	657.0	582	256	277	77	223	31	0	10	2,771	21	3.05	3.39	1.05	27.3	8.0	1.23	.300	3.79	81	3.40	78	7.97	70.6