Billy Koch had the most saves by a pitcher in his first 4 seasons, with 144 saves.

Interpreted as:

most regular-season saves by a player in first 4 years

	NAME	SV	G	W	L	W%	GS	ERA	SO	CG	SHO	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	Billy Koch B. Koch	144	277	22	17	.564	0	3.48	265	0	0	305.1	275	118	131	25	127	15	245	22	1,304	11	7.81	3.74	2.09	0.74	20.3	9.7	1.32	.287	3.86	75	3.78	83	8.11	27.4
2	Craig Kimbrel C. Kimbrel	139	231	15	7	.682	0	1.39	381	0	0	227.1	123	35	38	10	82	6	187	4	883	16	15.08	3.25	4.65	0.40	43.1	9.3	0.90	.280	1.50	37	1.43	38	4.87	60
3	Edwin Díaz E. Díaz	135	254	6	21	.222	0	3.33	400	0	0	249.0	188	92	97	35	86	16	188	7	1,029	15	14.46	3.11	4.65	1.27	38.9	8.4	1.10	.311	3.51	81	3.00	71	6.80	34.3
4	Joakim Soria J. Soria	132	238	8	10	.444	0	2.01	281	0	0	255.0	182	57	60	17	70	11	192	6	1,022	9	9.92	2.47	4.01	0.60	27.5	6.8	0.99	.257	2.12	45	2.75	64	6.42	43.9
5	Kazuhiro Sasaki K. Sasaki	129	228	7	16	.304	0	3.14	242	0	0	223.1	165	78	90	24	77	9	201	13	925	15	9.75	3.10	3.14	0.97	26.2	8.3	1.08	.246	3.63	72	3.42	77	6.65	25.4
6	Bobby Jenks B. Jenks	117	222	10	11	.476	0	3.09	224	0	0	235.2	196	81	85	13	76	5	190	21	960	14	8.55	2.90	2.95	0.50	23.3	7.9	1.15	.285	3.25	67	2.99	65	7.49	41.4
7	Roberto Osuna R. Osuna	116	244	10	15	.400	0	2.78	272	0	0	245.2	182	76	80	20	43	11	189	6	958	16	9.96	1.58	6.33	0.73	28.4	4.5	0.92	.265	2.93	66	2.64	63	6.67	43.2
8	Jonathan Papelbon J. Papelbon	113	202	13	10	.565	3	1.84	270	0	0	230.0	161	47	55	16	53	8	168	4	902	5	10.57	2.07	5.09	0.63	29.9	5.9	0.93	.261	2.15	40	2.49	58	6.30	47.1
9	Emmanuel Clase E. Clase	111	244	12	20	.375	1	2.00	236	0	0	238.1	182	53	81	11	48	3	190	7	946	13	8.91	1.81	4.92	0.42	24.9	5.1	0.97	.264	3.06	48	2.44	58	6.87	46.1
10	Troy Percival T. Percival	108	246	10	16	.385	0	2.77	353	0	0	266.2	160	82	90	25	116	10	174	12	1,086	12	11.91	3.91	3.04	0.84	32.5	10.7	1.03	.232	3.04	59	3.11	66	5.40	47.9
11	John Axford J. Axford	106	206	15	12	.556	0	3.06	264	0	0	208.2	167	71	81	15	97	3	166	7	887	23	11.39	4.18	2.72	0.65	29.8	10.9	1.27	.299	3.49	76	2.90	72	7.20	25.9
12	Todd Worrell T. Worrell	106	234	25	25	.500	0	2.58	260	0	0	310.0	258	89	97	26	116	2	179	43	1,279	10	7.55	3.37	2.24	0.75	20.3	9.1	1.21	.265	2.82	70	3.34	91	7.49	11.5
13	Bruce Sutter B. Sutter	105	240	27	22	.551	0	2.33	418	0	0	390.2	281	101	121	22	115	2	179	27	1,560	26	9.63	2.65	3.63	0.51	26.8	7.4	1.01	.258	2.79	58	2.16	56	6.47	72.9
14	Addison Reed A. Reed	101	198	9	13	.409	0	4.20	207	0	0	193.0	180	90	95	24	57	5	160	7	818	5	9.65	2.66	3.63	1.12	25.3	7.0	1.23	.297	4.43	104	3.52	88	8.39	10.9
15	Dan Plesac D. Plesac	100	210	19	19	.500	0	2.63	268	0	0	284.0	237	83	94	21	81	3	179	5	1,155	14	8.49	2.57	3.31	0.67	23.2	7.0	1.12	.276	2.98	63	2.75	68	7.51	42.2
16	Trevor Hoffman T. Hoffman	98	239	24	19	.558	0	3.13	310	0	0	287.1	217	100	107	30	104	3	180	27	1,182	11	9.71	3.26	2.98	0.94	26.2	8.8	1.12	.254	3.35	78	3.40	81	6.80	26
17	Dick Radatz D. Radatz	98	270	49	32	.605	0	2.57	608	0	0	538.1	396	154	164	42	202	21	234	35	2,208	11	10.16	3.38	3.01	0.70	27.5	9.1	1.11	.265	2.74	67	2.55	64	6.62	82.6
18	Trevor Rosenthal T. Rosenthal	96	233	6	16	.273	0	2.66	303	0	0	237.0	196	70	73	11	94	12	138	8	995	12	11.51	3.57	3.22	0.42	30.5	9.4	1.22	.322	2.77	72	2.48	66	7.44	33.5
19	Gregg Olson G. Olson	95	210	16	14	.533	0	2.43	245	0	0	244.0	198	66	69	6	116	5	176	19	1,031	22	9.04	4.28	2.11	0.22	23.8	11.3	1.29	.291	2.55	62	2.60	66	7.30	35.7
20	Huston Street H. Street	94	247	21	12	.636	0	2.88	271	0	0	269.0	210	86	94	18	78	5	174	16	1,082	7	9.07	2.61	3.47	0.60	25.0	7.2	1.07	.270	3.14	67	2.89	67	7.03	43.9
21	Rod Beck R. Beck	94	220	9	9	.500	0	2.45	250	0	0	272.1	221	74	79	29	54	6	170	10	1,082	9	8.26	1.78	4.63	0.96	23.1	5.0	1.01	.258	2.61	67	3.12	80	7.30	21.5
22	Chad Cordero C. Cordero	91	223	17	11	.607	0	2.61	225	0	0	241.1	186	70	81	31	85	6	165	12	1,004	6	8.39	3.17	2.65	1.16	22.4	8.5	1.12	.236	3.02	61	4.00	92	6.94	9
23	Bobby Thigpen B. Thigpen	91	200	16	19	.457	0	3.06	181	0	0	293.2	270	100	109	27	109	9	166	11	1,245	8	5.55	3.34	1.66	0.83	14.5	8.8	1.29	.264	3.34	75	3.96	100	8.27	1.2
24	Dan Quisenberry D. Quisenberry	91	219	25	20	.556	0	2.67	116	0	0	367.1	356	109	122	23	61	2	192	30	1,474	3	2.84	1.49	1.90	0.56	7.9	4.1	1.14	.262	2.99	66	3.40	86	8.72	22.1
25	Camilo Doval C. Doval	90	228	22	16	.579	0	3.33	282	0	0	221.1	178	82	104	16	104	14	160	12	947	23	11.47	4.23	2.71	0.65	29.8	11.0	1.27	.305	4.23	83	3.16	80	7.24	20.8