most seasons with a earn run average of 2.50 or less by a pitcher all-time

Mariano Rivera played the most seasons with an ERA of 2.50 or better, with 15 seasons.

	NAME	SEAS	ERA	G	W	L	W%	GS	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	Mariano Rivera M. Rivera	15	1.86	918	66	45	.595	0	949	0	0	558	1023.2	766	211	230	49	208	36	793	34	4,009	9	8.34	1.83	4.56	0.43	23.7	5.2	0.95	.259	2.02	42	2.57	58	6.73	215.7
2	Walter Johnson W. Johnson	13	1.65	544	297	191	.609	439	2,614	388	86	22	4090.2	3,145	749	1,103	31	818	142	99		15,736	129	5.75	1.80	3.20	0.07	16.6	5.2	0.97	.257	2.43	60	1.94	70	6.92	384.9
3	Eddie Plank E. Plank	13	2.15	479	256	149	.632	413	1,788	321	56	16	3507.0	2,996	839	1,138	29	844	154	55		13,826	62	4.59	2.17	2.12	0.07	12.9	6.1	1.09	.269	2.92	78	2.38	88	7.69	128.2
4	Hoyt Wilhelm H. Wilhelm	12	2.05	660	104	77	.575	38	1,057	17	4	148	1447.2	1,039	329	413	80	465	44	409	37	5,753	51	6.57	2.89	2.27	0.50	18.4	8.1	1.04	.234	2.57	57	2.82	78	6.46	131.6
5	Christy Mathewson C. Mathewson	12	1.90	511	315	142	.689	450	2,208	367	66	25	3915.2	3,333	825	1,223	56	700	49	55		15,346	101	5.07	1.61	3.15	0.13	14.4	4.6	1.03	.266	2.81	65	2.15	72	7.66	362.1
6	Billy Wagner B. Wagner	10	1.89	505	26	16	.619	0	718	0	0	255	543.0	328	114	139	47	163	20	409	15	2,125	18	11.90	2.70	4.40	0.78	33.8	7.7	0.90	.239	2.30	44	2.57	60	5.44	105.1
7	Clayton Kershaw C. Kershaw	9	2.08	230	135	42	.763	230	1,730	22	12	0	1540.2	1,110	356	398	118	291	21	0	6	5,919	48	10.11	1.70	5.95	0.69	29.2	4.9	0.91	.264	2.32	54	2.47	62	6.48	253.8
8	Joe Nathan J. Nathan	9	1.61	425	23	10	.697	0	509	0	0	247	423.2	267	76	80	24	124	9	369	17	1,651	22	10.81	2.63	4.10	0.51	30.8	7.5	0.92	.247	1.70	37	2.39	56	5.67	90
9	Ed Walsh E. Walsh	9	1.73	382	179	115	.609	284	1,623	233	54	33	2690.0	2,106	516	760	21	514	43	90		10,285	62	5.43	1.72	3.16	0.07	15.8	5.0	0.97	.258	2.54	66	1.92	76	7.05	175.5
10	Bill Donovan B. Donovan	9	2.28	183	103	57	.644	166	778	149	23	3	1477.2	1,246	374	516	17	449	43	17		5,917	29	4.74	2.73	1.73	0.10	13.1	7.6	1.15	.265	3.14	86	2.46	95	7.59	26
11	Rube Waddell R. Waddell	9	2.03	354	169	123	.579	298	2,079	225	49	3	2584.0	2,094	582	865	27	697	95	45		10,142	63	7.24	2.43	2.98	0.09	20.5	6.9	1.08	.285	3.01	72	1.90	69	7.29	250.2
12	Cy Young C. Young	9	1.91	376	234	118	.665	346	1,478	325	50	7	3188.0	2,689	675	1,003	43	451	65	28		12,292	49	4.17	1.27	3.28	0.12	12.0	3.7	0.98	.258	2.83	65	2.22	76	7.59	250.5
13	Aroldis Chapman A. Chapman	8	1.87	392	23	18	.561	0	651	0	0	218	386.0	211	80	90	17	163	17	310	1	1,534	41	15.18	3.80	3.99	0.40	42.4	10.6	0.97	.283	2.10	45	1.73	41	4.92	101.9
14	Darren O'Day D. O'Day	8	1.89	440	35	11	.761	0	412	0	0	14	405.1	280	85	93	33	98	35	95	11	1,599	2	9.15	2.18	4.20	0.73	25.8	6.1	0.93	.242	2.06	45	3.11	74	6.22	49.2
15	Tom Henke T. Henke	8	2.13	391	18	21	.462	0	517	0	0	201	473.2	344	112	122	38	136	4	344	17	1,875	19	9.82	2.58	3.80	0.72	27.6	7.3	1.01	.259	2.32	52	2.57	63	6.54	80.3
16	Rich Gossage R. Gossage	8	1.91	456	61	45	.575	0	798	0	0	210	814.0	569	173	206	39	299	13	375	44	3,254	16	8.82	3.31	2.67	0.43	24.5	9.2	1.07	.252	2.28	50	2.48	64	6.29	124.9
17	Babe Adams B. Adams	8	2.05	223	111	59	.653	184	630	116	30	5	1570.2	1,328	357	473	24	222	21	31		6,078	18	3.61	1.27	2.84	0.14	10.4	3.7	0.99	.252	2.71	66	2.42	77	7.61	122
18	Joe Wood J. Wood	8	1.93	201	107	53	.669	143	919	110	27	9	1303.1	1,023	280	447	9	378	49	48		5,123	38	6.35	2.61	2.43	0.06	17.9	7.4	1.07	.269	3.09	66	2.24	77	7.06	100.4
19	Chief Bender C. Bender	8	1.93	242	128	50	.719	176	912	135	29	25	1603.0	1,333	343	463	13	345	36	59		6,223	35	5.12	1.94	2.64	0.07	14.7	5.5	1.05	.268	2.60	72	2.05	77	7.48	102.8
20	Mordecai Brown M. Brown	8	1.62	301	177	74	.705	227	954	195	49	30	2158.1	1,657	389	582	14	425	40	70		8,247	40	3.98	1.77	2.24	0.06	11.6	5.2	0.96	.241	2.43	60	2.15	79	6.91	134.5
21	Addie Joss A. Joss	8	1.77	254	143	84	.630	231	814	206	40	5	2057.2	1,663	405	610	17	289	45	20		7,815	23	3.56	1.26	2.82	0.07	10.4	3.7	0.95	.248	2.67	68	2.16	86	7.27	77.2
22	Jim McCormick J. McCormick	8	2.23	414	221	180	.551	407	1,455	392	31	1	3605.2	3,374	892	1,713	52	565		7		14,836	137	3.63	1.41	2.58	0.13	9.8	3.8	1.09		4.28	84	2.68	99	8.42	-21.5
23	Kenley Jansen K. Jansen	7	1.90	425	24	13	.649	0	630	0	0	219	427.0	241	90	96	31	117	15	315	9	1,640	13	13.28	2.47	5.38	0.65	38.4	7.1	0.84	.248	2.02	49	2.03	51	5.08	94.1
24	Craig Kimbrel C. Kimbrel	7	1.55	424	24	15	.615	0	702	0	0	245	417.2	217	72	81	24	145	15	335	5	1,616	35	15.13	3.12	4.84	0.52	43.4	9.0	0.87	.264	1.75	39	1.63	42	4.68	107.5
25	Jonathan Papelbon J. Papelbon	7	1.94	446	22	22	.500	0	523	0	0	252	463.2	336	100	118	34	105	25	390	7	1,842	5	10.15	2.04	4.98	0.66	28.4	5.7	0.95	.261	2.29	46	2.67	65	6.52	76.1