Greg Maddux has the best win percentage by a Cy Young winner in a season, at .905 in 1995.

Interpreted as:

best w% in a cy young award in a regular season by a player winner

	NAME	W%	CY	SEASON	TM	W	L	G	GS	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	1	1995	ATL	19	2	28	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	1	1995	SEA	18	2	30	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	1	1978	NYY	25	3	35	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	Shane Bieber S. Bieber	.889	1	2020	CLE	8	1	12	12	1.63	122	0	0	0	77.1	46	14	15	7	21	1	0	0	297	5	14.20	2.44	5.81	0.81	41.1	7.1	0.87	.267	1.75	37	2.06	46	5.35	20.5
5	Cliff Lee C. Lee	.880	1	2008	CLE	22	3	31	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	1	2014	LAD	21	3	27	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	1	2013	DET	21	3	32	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	Dennis Eckersley D. Eckersley	.875	1	1992	OAK	7	1	69	0	1.91	93	0	0	51	80.0	62	17	17	5	11	1	65	6	309	0	10.46	1.24	8.45	0.56	30.1	3.6	0.91	.286	1.91	52	1.71	44	6.98	19.4
9	Roger Clemens R. Clemens	.870	1	2001	NYY	20	3	33	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	Whitey Ford W. Ford	.862	1	1961	NYY	25	4	39	39	3.21	209	11	3	0	283.0	242	101	108	23	92	1	0	3	1,159	8	6.65	2.93	2.27	0.73	18.0	7.9	1.18	.263	3.43	85	3.14	82	7.70	22.7
11	Chris Sale C. Sale	.857	1	2024	ATL	18	3	29	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
12	Roger Clemens R. Clemens	.857	1	1986	BOS	24	4	33	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
13	Dwight Gooden D. Gooden	.857	1	1985	NYM	24	4	35	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
14	Pedro Martinez P. Martinez	.852	1	1999	BOS	23	4	31	29	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
15	Rick Porcello R. Porcello	.846	1	2016	BOS	22	4	33	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
16	Denny McLain D. McLain	.838	1	1968	DET	31	6	41	41	1.96	280	28	6	0	336.0	241	73	86	31	63	6	0	2	1,288	3	7.50	1.69	4.44	0.83	21.7	4.9	0.90	.231	2.30	64	2.53	79	6.46	24.8
17	Sandy Koufax S. Koufax	.833	1	1963	LAD	25	5	40	40	1.88	306	20	11	0	311.0	214	65	68	18	58	3	0	7	1,210	6	8.86	1.68	5.28	0.52	25.3	4.8	0.87	.238	1.97	62	1.85	62	6.19	41.9
18	Justin Verlander J. Verlander	.828	1	2011	DET	24	5	34	34	2.40	250	4	2	0	251.0	174	67	73	24	57	3	0	0	969	7	8.96	2.04	4.39	0.86	25.8	5.9	0.92	.236	2.62	58	2.99	74	6.24	29.4
19	Randy Johnson R. Johnson	.828	1	2002	ARI	24	5	35	35	2.32	334	8	4	0	260.0	197	67	78	26	71	13	0	1	1,035	3	11.56	2.46	4.70	0.90	32.3	6.9	1.03	.289	2.70	54	2.65	61	6.82	47
20	Barry Zito B. Zito	.821	1	2002	OAK	23	5	35	35	2.75	182	1	0	0	229.1	182	70	79	24	78	9	0	2	939	2	7.14	3.06	2.33	0.94	19.4	8.3	1.13	.245	3.10	63	3.86	89	7.14	12.6
21	Tarik Skubal T. Skubal	.818	1	2024	DET	18	4	31	31	2.39	228	0	0	0	192.0	142	51	54	15	35	9	0	0	753	2	10.69	1.64	6.51	0.70	30.3	4.6	0.92	.273	2.53	60	2.49	61	6.66	33.5
22	Justin Verlander J. Verlander	.818	1	2022	HOU	18	4	28	28	1.75	185	0	0	0	175.0	116	34	43	12	29	6	0	0	666	3	9.51	1.49	6.38	0.62	27.8	4.4	0.83	.240	2.21	46	2.48	64	5.97	27.7
23	Corey Kluber C. Kluber	.818	1	2017	CLE	18	4	29	29	2.25	265	5	3	0	203.2	141	51	56	21	36	5	0	2	777	4	11.71	1.59	7.36	0.93	34.1	4.6	0.87	.267	2.47	50	2.49	57	6.23	42.8
24	Roger Clemens R. Clemens	.818	1	2004	HOU	18	4	33	33	2.98	218	0	0	0	214.1	169	71	76	15	79	6	0	5	878	5	9.15	3.32	2.76	0.63	24.8	9.0	1.16	.275	3.19	69	3.11	70	7.10	31.7
25	Bob Welch B. Welch	.818	1	1990	OAK	27	6	35	35	2.95	127	2	2	0	238.0	214	78	90	26	77	5	0	4	979	2	4.80	2.91	1.65	0.98	13.0	7.9	1.22	.253	3.40	79	4.19	110	8.09	-11.1