lowest whip in a season by a relief pitcher with at least 20 ip

Don Mossi has the lowest WHIP by a relief pitcher with 20.0+ innings pitched in a season, with a WHIP of 0.48 in 1963.

	NAME	WHIP	IP	SEASON	TM	G	W	L	W%	GS	ERA	SO	CG	SHO	SV	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	BABIP	RA	H/9
1	Don Mossi D. Mossi	0.48	25.0	1963	DET	8	2	0	1.000	0	0.72	12	0	0	2	12	2	3	2	0	0	5	0	85	0	4.32	0.00		0.72	14.1	0.0	.141	1.08	4.32
2	George Winter G. Winter	0.50	35.2	1907	BSA	8	2	1	.667	0		15	0	0	1	13		2	0	5	1	8			0	3.79	1.26	3.00	0.00				0.50	3.28
3	Sean Guenther S. Guenther	0.52	21.0	2024	DET	17	3	0	1.000	0	0.86	12	0	0	0	9	2	2	0	2	2	4	0	73	0	5.14	0.86	6.00	0.00	16.4	2.7	.158	0.86	3.86
4	Dutch Leonard D. Leonard	0.54	26.0	1914	BSA	11	4	0	1.000	0	0.35	28	0	0	3	5	1	2	0	9	2	9		93	1	9.69	3.12	3.11	0.00	30.1	9.7	.093	0.69	1.73
5	Steve Howe S. Howe	0.55	22.0	1992	NYY	20	3	0	1.000	0	2.45	12	0	0	6	9	6	7	1	3	0	10	1	79	1	4.91	1.23	4.00	0.41	15.2	3.8	.127	2.86	3.68
6	Ed Walsh E. Walsh	0.55	25.2	1910	CWS	9	2	2	.500	0		21	0	0	5	10		3	1	4	0	8		92	2	7.36	1.40	5.25	0.35	22.8	4.3	.136	1.05	3.51
7	Koji Uehara K. Uehara	0.57	74.1	2013	BOS	73	4	1	.800	0	1.09	101	0	0	21	33	9	10	5	9	1	40	2	265	1	12.23	1.09	11.22	0.61	38.1	3.4	.188	1.21	4.00
8	Steven Okert S. Okert	0.57	26.1	2025	HOU	23	1	1	.500	0	2.05	32	0	0	1	12	6	6	2	3	2	3	0	96	0	10.94	1.03	10.67	0.68	33.3	3.1	.175	2.05	4.10
9	Jason Dickson J. Dickson	0.58	20.2	1998	ANA	9	3	0	1.000	0	0.87	10	0	0	0	10	2	2	0	2	1	5	0	72	0	4.35	0.87	5.00	0.00	13.9	2.8	.169	0.87	4.35
10	Sergio Santos S. Santos	0.58	25.2	2013	TOR	29	1	1	.500	0	1.75	28	0	0	1	11	5	5	1	4	0	6	2	90	1	9.82	1.40	7.00	0.35	31.1	4.4	.175	1.75	3.86
11	J.P. Feyereisen	0.59	20.1	2022	TBR	20	4	0	1.000	0	0.00	20	0	0	1	7	0	1	0	5	0	3	0	74	0	8.85	2.21	4.00	0.00	27.0	6.8	.143	0.44	3.10
12	Mike Adams M. Adams	0.59	37.0	2009	SDP	37	0	0		0	0.73	45	0	0	0	14	3	9	1	8	0	5	1	136	1	10.95	1.95	5.63	0.24	33.1	5.9	.159	2.19	3.41
13	Sean Doolittle S. Doolittle	0.60	45.0	2018	WSH	43	3	3	.500	0	1.60	60	0	0	25	21	8	8	3	6	2	35	1	163	1	12.00	1.20	10.00	0.60	36.8	3.7	.196	1.60	4.20
14	Valerio De Los Santos V. De Los Santos	0.60	21.2	1998	MIL	13	0	0		0	2.91	18	0	0	0	11	7	7	4	2	0	3	0	75	1	7.48	0.83	9.00	1.66	24.0	2.7	.137	2.91	4.57
15	Andy Messersmith A. Messersmith	0.60	23.1	1970	CAL	11	3	0	1.000	0	0.77	29	0	0	5	9	2	2	1	5	0	8	1	83	0	11.19	1.93	5.80	0.39	34.9	6.0	.167	0.77	3.47
16	Dennis Eckersley D. Eckersley	0.61	57.2	1989	OAK	51	4	0	1.000	0	1.56	55	0	0	33	32	10	10	5	3	1	46	0	206	0	8.58	0.47	18.33	0.78	26.7	1.5	.190	1.56	4.99
17	Ray Caldwell R. Caldwell	0.61	21.1	1914	NYY	8	3	1	.750	0	3.38	16	0	0	0	10	8	9	1	3	1	7		77	1	6.75	1.27	5.33	0.42	20.8	3.9	.161	3.80	4.22
18	Dennis Eckersley D. Eckersley	0.61	73.1	1990	OAK	63	4	2	.667	0	0.61	73	0	0	48	41	5	9	2	4	0	61	1	262	0	8.96	0.49	18.25	0.25	27.9	1.5	.213	1.10	5.03
19	Karl Spooner K. Spooner	0.62	32.1	1955	BKN	15	5	1	.833	0	1.11	30	0	0	2	12	4	4	0	8	3	10	1	117	0	8.35	2.23	3.75	0.00	25.6	6.8	.158	1.11	3.34
20	Devin Williams D. Williams	0.63	27.0	2020	MIL	22	4	1	.800	0	0.33	53	0	0	0	8	1	4	1	9	1	1	0	100	3	17.67	3.00	5.89	0.33	53.0	9.0	.194	1.33	2.67
21	Randy Rodríguez R. Rodríguez	0.64	26.2	2025	SFG	25	3	0	1.000	0	0.68	38	0	0	0	14	2	2	1	3	1	4	0	96	0	12.83	1.01	12.67	0.34	39.6	3.1	.245	0.68	4.72
22	Koji Uehara K. Uehara	0.64	36.0	2012	TEX	37	0	0		0	1.75	43	0	0	1	20	7	7	4	3	0	13	0	130	1	10.75	0.75	14.33	1.00	33.1	2.3	.200	1.75	5.00
23	Reynaldo López R. López	0.64	20.1	2021	CWS	11	2	1	.667	0	2.21	22	0	0	0	10	5	6	3	3	0	3	0	73	1	9.74	1.33	7.33	1.33	30.1	4.1	.156	2.66	4.43
24	Joe Boever J. Boever	0.64	20.1	1988	ATL	16	0	2	.000	0	1.77	7	0	0	1	12	4	4	1	1	1	13	0	70	0	3.10	0.44	7.00	0.44	10.0	1.4	.183	1.77	5.31
25	Arnie Portocarrero A. Portocarrero	0.64	34.1	1957	KCA	16	2	0	1.000	0	0.52	15	0	0	0	17	2	3	0	5	1	8	1	124	0	3.93	1.31	3.00	0.00	12.1	4.0	.165	0.79	4.46