most single season wins by an a's pitcher

Lefty Grove and Jack Coombs are tied for winning the most games for the Philadelphia Athletics in a season, with 31 wins.

	NAME	W	SEASON	TM	L	W%	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	Lefty Grove L. Grove	31	1931	PHA	4	.886	41	30	2.06	175	27	4	5	288.2	249	66	84	10	62	1	10		1,160	2	5.46	1.93	2.82	0.31	15.1	5.3	1.08	.262	2.62	47	3.01	70	7.76	40.8
2	Jack Coombs J. Coombs	31	1910	PHA	9	.775	45	38	1.30	224	35	13	1	353.0	248	51	74	0	115	7	6		1,353	10	5.71	2.93	1.95	0.00	16.6	8.5	1.03	.246	1.89	53	2.09	83	6.32	15.8
3	Lefty Grove L. Grove	28	1930	PHA	5	.848	50	32	2.54	209	22	2	9	291.0	273	82	101	8	60	5	17		1,191	2	6.46	1.86	3.48	0.25	17.5	5.0	1.14	.292	3.12	53	3.09	64	8.44	55.6
4	Jack Coombs J. Coombs	28	1911	PHA	12	.700	47	40	3.53	185	26	1	2	336.2	360	132	166	8	119	16	6		1,422	12	4.95	3.18	1.55	0.21	13.0	8.4	1.42	.322	4.44	109	3.18	103	9.62	-4.6
5	Bob Welch B. Welch	27	1990	OAK	6	.818	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
6	Eddie Rommel E. Rommel	27	1922	PHA	13	.675	51	33	3.28	54	22	3	2	294.0	294	107	128	21	63	5	16		1,203	3	1.65	1.93	0.86	0.64	4.5	5.2	1.21	.258	3.92	80	4.26	102	9.00	-2.3
7	Rube Waddell R. Waddell	27	1905	PHA	10	.730	46	34	1.48	287	27	7	0	328.2	231	54	86	5	90	10	11		1,257	10	7.86	2.46	3.19	0.14	22.8	7.2	0.98	.261	2.35	55	1.89	69	6.33	31.2
8	Eddie Plank E. Plank	26	1912	PHA	6	.813	37	30	2.22	110	23	5	2	259.2	234	64	90	1	83	6	7		1,044	5	3.81	2.88	1.33	0.03	10.5	8.0	1.22	.276	3.12	69	3.08	99	8.11	-0.7
9	Eddie Plank E. Plank	26	1904	PHA	17	.605	44	43	2.17	201	37	7	0	357.1	311	86	111	2	86	19	1		1,427	6	5.06	2.17	2.34	0.05	14.1	6.0	1.11	.276	2.80	82	2.25	88	7.83	13.1
10	Catfish Hunter C. Hunter	25	1974	OAK	12	.676	41	41	2.49	143	23	6	0	318.1	268	88	97	25	46	4	0	2	1,240	1	4.04	1.30	3.11	0.71	11.5	3.7	0.99	.238	2.74	73	3.16	86	7.58	17.6
11	Lefty Grove L. Grove	25	1932	PHA	10	.714	44	30	2.84	188	27	4	7	291.2	269	92	101	13	79	1	13		1,207	0	5.80	2.44	2.38	0.40	15.6	6.5	1.19	.276	3.12	63	3.13	72	8.30	40.2
12	Rube Waddell R. Waddell	25	1904	PHA	19	.568	46	46	1.62	349	39	8	0	383.0	307	69	109	5	91	14	0		1,496	8	8.20	2.14	3.84	0.12	23.3	6.1	1.04	.291	2.56	61	1.59	62	7.21	41.5
13	Vida Blue V. Blue	24	1971	OAK	8	.750	39	39	1.82	301	24	8	0	312.0	209	63	73	19	88	4	0	3	1,207	10	8.68	2.54	3.42	0.55	24.9	7.3	0.95	.239	2.11	56	2.19	66	6.03	41.4
14	Bobby Shantz B. Shantz	24	1952	PHA	7	.774	33	33	2.48	152	27	5	0	279.2	230	77	87	21	63	4	0		1,103	0	4.89	2.03	2.41	0.68	13.8	5.7	1.05	.242	2.80	65	3.00	79	7.40	25
15	Lefty Grove L. Grove	24	1933	PHA	8	.750	45	28	3.20	114	21	2	6	275.1	280	98	113	12	83	4	16		1,173	1	3.73	2.71	1.37	0.39	9.7	7.1	1.32	.279	3.69	74	3.48	85	9.15	18.6
16	George Earnshaw G. Earnshaw	24	1929	PHA	8	.750	44	33	3.29	149	13	3	1	254.2	233	93	110	8	125	5	5		1,115	8	5.27	4.42	1.19	0.28	13.4	11.2	1.41	.272	3.89	78	3.93	90	8.23	12.9
17	Lefty Grove L. Grove	24	1928	PHA	8	.750	39	31	2.58	183	24	4	3	261.2	228	75	93	10	64	1	6		1,064	4	6.29	2.20	2.86	0.34	17.2	6.0	1.12	.270	3.20	63	2.75	70	7.84	34.9
18	Eddie Plank E. Plank	24	1907	PHA	16	.600	43	40	2.20	183	33	8	0	343.2	282	84	115	5	85	17	3		1,349	5	4.79	2.23	2.15	0.13	13.6	6.3	1.07	.262	3.01	85	2.19	90	7.39	9.5
19	Eddie Plank E. Plank	24	1905	PHA	12	.667	41	41	2.26	210	35	4	0	346.2	287	87	113	3	75	24	0		1,362	9	5.45	1.95	2.80	0.08	15.4	5.5	1.04	.270	2.93	84	2.28	83	7.45	17.9
20	Rube Waddell R. Waddell	24	1902	PHA	7	.774	33	27	2.05	210	26	3	0	276.1	224	63	90	7	64	10	5		1,081	10	6.84	2.08	3.28	0.23	19.4	5.9	1.04	.275	2.93	56	2.28	65	7.30	38.6
21	Barry Zito B. Zito	23	2002	OAK	5	.821	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
22	Eddie Plank E. Plank	23	1911	PHA	8	.742	40	30	2.10	149	24	6	4	256.2	237	60	85	2	77	14	8		1,020	5	5.22	2.70	1.94	0.07	14.6	7.5	1.22	.302	2.98	65	2.77	89	8.31	8.5
23	Chief Bender C. Bender	23	1910	PHA	5	.821	30	28	1.58	155	25	3	0	250.0	182	44	63	1	47	10	2		936	7	5.58	1.69	3.30	0.04	16.6	5.0	0.92	.250	2.27	65	1.82	72	6.55	19
24	Eddie Plank E. Plank	23	1903	PHA	16	.590	43	40	2.38	176	33	3	0	336.0	317	89	128	5	65	23	2		1,363	8	4.71	1.74	2.71	0.13	12.9	4.8	1.14	.285	3.43	78	2.68	89	8.49	13.9
25	Dave Stewart D. Stewart	22	1990	OAK	11	.667	36	36	2.56	166	11	4	0	267.0	226	76	84	16	83	5	0	1	1,088	8	5.60	2.80	2.00	0.54	15.3	7.6	1.16	.257	2.83	69	3.32	88	7.62	13.9