highest win percentage by a pitcher in a season minimum 25 games started after 1970

Since 1971, Greg Maddux has the highest win percentage with 25+ starts in a season, at .905 in 1995.

	NAME	W%	GS	SEASON	TM	W	L	G	ERA	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	ERA-	FIP	FIP-	H/9	PRAA
1	Greg Maddux G. Maddux	.905	28	1995	ATL	19	2	28	1.63	181	10	3	0	209.2	147	38	39	8	23	4	0	3	785	1	7.77	0.99	7.87	0.34	23.1	2.9	0.81	.244	1.67	39	2.25	52	6.31	46.9
2	Randy Johnson R. Johnson	.900	30	1995	SEA	18	2	30	2.48	294	6	3	0	214.1	159	59	65	12	65	6	0	1	866	5	12.35	2.73	4.52	0.50	33.9	7.5	1.05	.301	2.73	53	2.08	44	6.68	62
3	Ron Guidry R. Guidry	.893	35	1978	NYY	25	3	35	1.74	248	16	9	0	273.2	187	53	61	13	72	1	0	1	1,057	7	8.16	2.37	3.44	0.43	23.5	6.8	0.95	.241	2.01	48	2.18	58	6.15	48.5
4	Aaron Sanchez A. Sanchez	.882	30	2016	TOR	15	2	30	3.00	161	0	0	0	192.0	161	64	69	15	63	5	0	0	790	5	7.55	2.95	2.56	0.70	20.4	8.0	1.17	.267	3.23	71	3.54	83	7.55	14.9
5	Cliff Lee C. Lee	.880	31	2008	CLE	22	3	31	2.54	170	4	2	0	223.1	214	63	68	12	34	5	0	1	891	4	6.85	1.37	5.00	0.48	19.1	3.8	1.11	.301	2.74	59	2.82	67	8.62	35.4
6	Clayton Kershaw C. Kershaw	.875	27	2014	LAD	21	3	27	1.77	239	6	2	0	198.1	139	39	42	9	31	2	0	0	749	7	10.85	1.41	7.71	0.41	31.9	4.1	0.86	.278	1.91	51	1.81	50	6.31	40.5
7	Max Scherzer M. Scherzer	.875	32	2013	DET	21	3	32	2.90	240	0	0	0	214.1	152	69	73	18	56	4	0	0	836	6	10.08	2.35	4.29	0.76	28.7	6.7	0.97	.259	3.07	72	2.74	69	6.38	29.2
8	Julio Urías J. Urías	.870	32	2021	LAD	20	3	32	2.96	195	0	0	0	185.2	151	61	67	19	38	7	0	3	745	2	9.45	1.84	5.13	0.92	26.2	5.1	1.02	.272	3.25	73	3.12	73	7.32	23.8
9	Roger Clemens R. Clemens	.870	33	2001	NYY	20	3	33	3.51	213	0	0	0	220.1	205	86	94	19	72	5	0	1	918	14	8.70	2.94	2.96	0.78	23.2	7.8	1.26	.305	3.84	80	3.28	74	8.37	28.1
10	David Cone D. Cone	.870	28	1988	NYM	20	3	35	2.22	213	8	4	0	231.1	178	57	67	10	80	4	0	7	936	10	8.29	3.11	2.66	0.39	22.8	8.5	1.12	.267	2.61	68	2.57	75	6.93	22.5
11	Zack Greinke Z. Greinke	.864	32	2015	LAD	19	3	32	1.66	200	1	0	0	222.2	148	41	43	14	40	5	0	1	843	7	8.08	1.62	5.00	0.57	23.7	4.7	0.84	.229	1.74	44	2.75	73	5.98	26.2
12	Orel Hershiser O. Hershiser	.864	34	1985	LAD	19	3	36	2.03	157	9	5	0	239.2	179	54	72	8	68	6	1	5	953	5	5.90	2.55	2.31	0.30	16.5	7.1	1.03	.239	2.70	59	2.73	77	6.72	22.1
13	Chris Sale C. Sale	.857	29	2024	ATL	18	3	29	2.38	225	0	0	0	177.2	141	47	48	9	39	8	0	0	702	4	11.40	1.98	5.77	0.46	32.1	5.6	1.01	.314	2.43	57	2.08	52	7.14	38.1
14	Daisuke Matsuzaka D. Matsuzaka	.857	29	2008	BOS	18	3	29	2.90	154	0	0	0	167.2	128	54	58	12	94	7	0	1	716	5	8.27	5.05	1.64	0.64	21.5	13.1	1.32	.258	3.11	64	4.02	96	6.87	2.9
15	Roger Clemens R. Clemens	.857	33	1986	BOS	24	4	33	2.48	238	10	1	0	254.0	179	70	77	21	67	4	0	0	997	11	8.43	2.37	3.55	0.74	23.9	6.7	0.97	.237	2.73	58	2.80	69	6.34	36.3
16	Dwight Gooden D. Gooden	.857	35	1985	NYM	24	4	35	1.53	268	16	8	0	276.2	198	47	51	13	69	2	0	4	1,065	6	8.72	2.24	3.88	0.42	25.2	6.5	0.97	.259	1.66	44	2.12	59	6.44	45.6
17	Pedro Martinez P. Martinez	.852	29	1999	BOS	23	4	31	2.07	313	5	1	0	213.1	160	49	56	9	37	9	1	1	835	6	13.20	1.56	8.46	0.38	37.5	4.4	0.92	.323	2.36	42	1.38	30	6.75	79.4
18	John Smoltz J. Smoltz	.850	26	1998	ATL	17	3	26	2.90	173	2	2	0	167.2	145	54	58	10	44	4	0	2	681	3	9.29	2.36	3.93	0.54	25.4	6.5	1.13	.300	3.11	69	2.70	63	7.78	29.2
19	Rick Porcello R. Porcello	.846	33	2016	BOS	22	4	33	3.15	189	3	0	0	223.0	193	78	85	23	32	13	0	0	890	3	7.63	1.29	5.91	0.93	21.2	3.6	1.01	.269	3.43	71	3.39	81	7.79	20.1
20	Mike Hampton M. Hampton	.846	34	1999	HOU	22	4	34	2.90	177	3	2	0	239.0	206	77	86	12	101	5	0	2	979	9	6.67	3.80	1.75	0.45	18.1	10.3	1.28	.284	3.24	68	3.63	84	7.76	19.4
21	Alex Wood A. Wood	.842	25	2017	LAD	16	3	27	2.72	151	0	0	0	152.1	123	46	50	15	38	6	0	6	614	2	8.92	2.25	3.97	0.89	24.6	6.2	1.06	.267	2.95	65	3.31	78	7.27	15.7
22	Kyle Lohse K. Lohse	.842	33	2012	STL	16	3	33	2.86	143	0	0	0	211.0	192	67	74	19	38	4	0	1	864	1	6.10	1.62	3.76	0.81	16.6	4.4	1.09	.262	3.16	74	3.50	91	8.19	8.5
23	Ian Kennedy I. Kennedy	.840	33	2011	ARI	21	4	33	2.88	198	1	1	0	222.0	186	71	73	19	55	9	0	0	900	11	8.03	2.23	3.60	0.77	22.0	6.1	1.09	.270	2.96	73	3.21	83	7.54	16.5
24	Shota Imanaga S. Imanaga	.833	29	2024	CHC	15	3	29	2.91	174	0	0	0	173.1	149	56	66	27	28	3	0	0	694	3	9.03	1.45	6.21	1.40	25.1	4.0	1.02	.264	3.43	73	3.71	93	7.74	5
25	Charlie Morton C. Morton	.833	30	2018	HOU	15	3	30	3.13	201	0	0	0	167.0	130	58	63	18	64	16	0	0	695	4	10.83	3.45	3.14	0.97	28.9	9.2	1.16	.283	3.40	76	3.59	87	7.01	10.4