The Seattle Mariners have managed a win percentage of .478 all-time.

	TEAM	W%	SEASON	W	L	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Mariners	.395	1977	64	98	162	5,460	624	1,398	218	33	133	589	426	35	769	110	67	6,044	2,081	384	81	42	22	114	.256	.312	.381	.693
2	Mariners	.350	1978	56	104	160	5,358	614	1,327	229	37	97	571	522	22	702	123	47	6,023	1,921	363	68	53	25	112	.248	.314	.359	.673
3	Mariners	.414	1979	67	95	162	5,544	711	1,490	250	52	132	676	515	28	725	126	52	6,202	2,240	434	61	54	45	158	.269	.331	.404	.735
4	Mariners	.364	1980	59	103	163	5,489	610	1,359	211	35	104	564	483	19	727	116	62	6,141	1,952	350	106	44	44	136	.248	.308	.356	.664
5	Mariners	.404	1981	44	65	110	3,780	426	950	148	13	89	406	329	27	553	100	50	4,201	1,391	250	41	24	24	70	.251	.314	.368	.682
6	Mariners	.469	1982	76	86	162	5,626	651	1,431	259	33	130	614	456	22	806	131	82	6,181	2,146	422	42	35	31	113	.254	.311	.381	.692
7	Mariners	.370	1983	60	102	162	5,336	558	1,280	247	31	111	536	460	24	840	144	80	5,905	1,922	389	40	45	31	113	.240	.301	.360	.661
8	Mariners	.457	1984	74	88	162	5,546	682	1,429	244	34	129	635	519	42	871	116	62	6,211	2,128	407	66	38	35	101	.258	.324	.384	.708
9	Mariners	.457	1985	74	88	162	5,521	719	1,410	277	38	171	686	564	31	942	94	35	6,185	2,276	486	28	41	36	147	.255	.326	.412	.738
10	Mariners	.414	1986	67	95	162	5,498	718	1,392	243	41	158	681	572	34	1,148	93	76	6,185	2,191	442	52	29	38	125	.253	.326	.399	.724
11	Mariners	.481	1987	78	84	162	5,508	760	1,499	282	48	161	717	500	43	863	174	73	6,139	2,360	491	38	50	19	132	.272	.335	.428	.763
12	Mariners	.422	1988	68	93	161	5,436	664	1,397	271	27	148	617	461	38	787	95	61	6,017	2,166	446	40	42	24	135	.257	.317	.398	.716
13	Mariners	.451	1989	73	89	162	5,512	694	1,417	237	29	134	653	489	45	838	81	55	6,133	2,114	400	35	52	40	109	.257	.320	.384	.703
14	Mariners	.475	1990	77	85	162	5,474	640	1,419	251	26	107	610	596	40	749	105	51	6,205	2,043	384	41	54	41	140	.259	.333	.373	.707
15	Mariners	.512	1991	83	79	162	5,494	702	1,400	268	29	126	665	588	37	811	97	44	6,236	2,104	423	55	62	57	139	.255	.328	.383	.711
16	Mariners	.395	1992	64	98	162	5,564	679	1,466	278	24	149	638	474	38	841	100	55	6,179	2,239	451	52	51	47	148	.263	.323	.402	.725
17	Mariners	.506	1993	82	80	162	5,494	734	1,429	272	24	161	681	624	56	901	91	68	6,288	2,232	457	63	51	73	132	.260	.339	.406	.745
18	Mariners	.438	1994	49	63	112	3,883	569	1,045	211	18	153	549	372	26	652	48	21	4,361	1,751	382	48	32	42	87	.269	.335	.451	.786
19	Mariners	.545	1995	79	66	145	4,996	796	1,377	276	20	182	767	549	39	871	110	41	5,670	2,239	478	52	34	53	109	.276	.350	.448	.798
20	Mariners	.528	1996	85	76	161	5,668	993	1,625	343	19	245	954	670	75	1,052	90	39	6,517	2,741	607	46	58	57	121	.287	.366	.484	.850
21	Mariners	.556	1997	90	72	162	5,614	925	1,574	312	21	264	890	626	49	1,110	89	40	6,384	2,720	597	46	49	53	146	.280	.355	.485	.839
22	Mariners	.472	1998	76	85	161	5,628	859	1,553	321	28	234	822	558	57	1,081	115	39	6,327	2,632	583	36	48	26	107	.276	.345	.468	.812
23	Mariners	.488	1999	79	83	162	5,572	859	1,499	263	21	244	825	610	42	1,095	130	45	6,310	2,536	528	38	48	38	114	.269	.343	.455	.798
24	Mariners	.562	2000	91	71	162	5,497	907	1,481	300	26	198	869	775	48	1,073	122	56	6,444	2,427	524	63	61	34	129	.269	.361	.442	.803
25	Mariners	.716	2001	116	46	162	5,680	927	1,637	310	38	169	881	614	62	989	174	42	6,474	2,530	517	48	70	54	112	.288	.360	.445	.805
	Total	.478		3,666	4,005	7,673	261,739	34,072	67,224	12,514	1,263	7,837	32,370	24,800	2,391	50,393	5,104	2,184	292,982	105,775	21,614	1,960	2,092	1,680	5,728	.257	.324	.404	.729