highest winning percentage for a relief pitcher all-time (min25 decisions)

Rube Waddell has the highest career win percentage by a relief pitcher with 25+ decisions, at .880.

	NAME	W%	DEC	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	H/9
1	Rube Waddell R. Waddell	.880	25	22	3	58	0	0.15	151	0	0	5	185.1	143		65	2	54	6	45			6	7.33	2.62	2.80	0.10		26.3	1.06	-17.625	3.16	6.94
2	George Mullin G. Mullin	.821	28	23	5	59	0	0.95	82	0	0	8	207.1	175		84	2	79	7	51			2	3.56	3.43	1.04	0.09		23.7	1.23	1.055	3.65	7.60
3	Christy Mathewson C. Mathewson	.789	38	30	8	79	0	1.30	104	0	0	25	214.1	164		72	6	26	3	70			2	4.37	1.09	4.00	0.25		3.4	0.89	.252	3.02	6.89
4	Charley Hall C. Hall	.781	32	25	7	108	0	1.08	164	0	0	12	348.2	293		166	7	159	11	89		1,450	6	4.23	4.10	1.03	0.18	11.3	11.0	1.30	.258	4.28	7.56
5	Joe Black J. Black	.765	34	26	8	156	0	3.74	181	0	0	25	327.0	303	136	146	42	108	1	93	7	1,369	0	4.98	2.97	1.68	1.16	13.2	7.9	1.26	.252	4.02	8.34
6	Brendan Donnelly B. Donnelly	.762	42	32	10	386	0	3.22	369	0	0	6	385.1	326	138	153	35	154	19	97	12	1,632	15	8.62	3.60	2.40	0.82	22.6	9.4	1.25	.276	3.57	7.61
7	Gene Packard G. Packard	.760	25	19	6	95	0	2.39	112	0	0	15	286.0	266	76	98	5	58	11	76			8	3.52	1.83	1.93	0.16		6.3	1.13	.355	3.08	8.37
8	Dan Otero D. Otero	.733	30	22	8	358	0	3.39	262	0	0	3	403.2	433	152	167	37	56	10	89	19	1,658	6	5.84	1.25	4.68	0.82	15.8	3.4	1.21	.306	3.72	9.65
9	Brad Clontz B. Clontz	.733	30	22	8	272	0	4.34	210	0	0	8	277.2	276	134	147	30	120	12	63	26	1,209	4	6.81	3.89	1.75	0.97	17.4	9.9	1.43	.294	4.76	8.95
10	Brent Suter B. Suter	.727	44	32	12	292	0	3.13	324	0	0	3	385.0	356	134	165	44	105	14	78	5	1,595	6	7.57	2.45	3.09	1.03	20.3	6.6	1.20	.282	3.86	8.32
11	Jeremy Jeffress J. Jeffress	.727	44	32	12	413	0	3.05	387	0	0	52	422.1	383	143	158	31	175	19	144	20	1,783	22	8.25	3.73	2.21	0.66	21.7	9.8	1.32	.301	3.37	8.16
12	Ken Holloway K. Holloway	.724	29	21	8	175	0	4.56	126	0	0	18	414.2	499	210	256	21	146	15	100		1,847	6	2.73	3.17	0.86	0.46	6.8	7.9	1.56	.311	5.56	10.83
13	Lefty Leifield L. Leifield	.724	29	21	8	80	0	1.51	106	0	0	7	238.2	232		100	3	72	13	58		992	3	4.00	2.72	1.47	0.11	10.7	7.3	1.27	.287	3.77	8.75
14	Johnny Lanning J. Lanning	.722	36	26	10	174	0	3.49	135	0	0	13	407.1	409	158	193	22	144	3	92		1,732	7	2.98	3.18	0.94	0.49	7.8	8.3	1.36	.271	4.26	9.04
15	Sean Lowe S. Lowe	.720	25	18	7	226	0	4.66	226	0	0	3	330.1	353	171	184	37	157	22	47	17	1,476	12	6.16	4.28	1.44	1.01	15.3	10.6	1.54	.306	5.01	9.62
16	Russ Kemmerer R. Kemmerer	.720	25	18	7	193	0	4.03	184	0	0	8	397.1	398	178	196	37	120	6	60	7	1,671	21	4.17	2.72	1.53	0.84	11.0	7.2	1.30	.273	4.44	9.02
17	Roxie Lawson R. Lawson	.720	25	18	7	125	0	4.73	91	0	0	11	344.2	357	181	211	33	212	2	78		1,567	5	2.38	5.54	0.43	0.86	5.8	13.5	1.65	.264	5.51	9.32
18	Larry Cheney L. Cheney	.720	25	18	7	88	0	2.49	122	0	0	20	234.2	203	65	92	3	96	3	62		984	22	4.68	3.68	1.27	0.12	12.4	9.8	1.27	.263	3.53	7.79
19	Collin McHugh C. McHugh	.714	28	20	8	219	0	2.89	321	0	0	1	292.1	243	94	104	24	84	18	49	6	1,199	5	9.88	2.59	3.82	0.74	26.8	7.0	1.12	.291	3.20	7.48
20	Carl Hubbell C. Hubbell	.714	28	20	8	102	0	1.95	122	0	0	33	231.0	201	50	58	6	46	4	82		920	7	4.75	1.79	2.65	0.23	13.3	5.0	1.07	.263	2.26	7.83
21	Joe Wood J. Wood	.714	28	20	8	67	0	0.73	139	0	0	10	159.1	134		64	0	52	5	58		641	9	7.85	2.94	2.67	0.00	21.7	8.1	1.17	.301	3.62	7.57
22	Sandy Consuegra S. Consuegra	.710	31	22	9	177	0	2.74	91	0	0	28	348.1	351	106	126	12	90	3	91	7	1,446	4	2.35	2.33	1.01	0.31	6.3	6.2	1.27	.271	3.26	9.07
23	Ryan Yarbrough R. Yarbrough	.709	55	39	16	136	0	3.74	336	0	0	2	419.0	375	174	181	54	115	36	27	10	1,744	3	7.22	2.47	2.92	1.16	19.3	6.6	1.17	.267	3.89	8.05
24	Hugh Casey H. Casey	.708	72	51	21	287	0	3.11	223	0	0	54	570.0	536	197	230	29	225	10	189		2,441	8	3.52	3.55	0.99	0.46	9.1	9.2	1.34	.259	3.63	8.46
25	Peter Moylan P. Moylan	.706	34	24	10	499	0	3.10	324	0	0	4	418.2	370	144	170	30	180	21	74	34	1,768	14	6.96	3.87	1.80	0.64	18.3	10.2	1.31	.280	3.65	7.95