Between the 2004 and 2008 seasons, Roger Clemens had the best ERA, with an ERA of 2.68.

Interpreted as:

best with a minimum of 0.5 IP per team game pitcher 2004 to 2008

	NAME	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	Roger Clemens R. Clemens	2.68	102	44	24	.647	101	573	1	0	0	638.0	508	190	213	42	201	18	0	11	2,587	18	8.08	2.84	2.85	0.59	22.1	7.8	1.11	.266	3.00	61	3.17	72	7.17	87.8
2	Johan Santana J. Santana	2.82	168	86	39	.688	168	1,189	9	6	0	1146.2	911	359	388	126	261	22	0	6	4,556	35	9.33	2.05	4.56	0.99	26.1	5.7	1.02	.265	3.05	64	3.20	74	7.15	143
3	Chris Volstad C. Volstad	2.88	15	6	4	.600	14	52	0	0	0	84.1	76	27	30	3	36	5	0	4	365	0	5.55	3.84	1.44	0.32	14.2	9.9	1.33	.271	3.20	67	3.81	89	8.11	4.3
4	Jake Peavy J. Peavy	2.95	150	68	44	.607	150	1,010	6	3	0	968.2	810	317	336	84	292	35	0	24	3,959	18	9.38	2.71	3.46	0.78	25.5	7.4	1.14	.286	3.12	74	3.17	75	7.53	117.4
5	Rich Harden R. Harden	3.06	94	36	16	.692	88	545	2	1	0	538.0	409	183	199	42	222	9	2	9	2,203	13	9.12	3.71	2.45	0.70	24.7	10.1	1.17	.265	3.33	69	3.35	76	6.84	63.2
6	Chris Carpenter C. Carpenter	3.11	98	51	20	.718	97	559	13	7	0	666.2	592	230	248	63	137	22	0	5	2,687	12	7.55	1.85	4.08	0.85	20.8	5.1	1.09	.278	3.35	73	3.33	77	7.99	72.3
7	Scot Shields S. Shields	3.11	347	35	29	.547	0	432	0	0	19	425.0	351	147	170	32	163	12	71	13	1,770	32	9.15	3.45	2.65	0.68	24.4	9.2	1.21	.282	3.60	70	3.28	75	7.43	51.7
8	John Smoltz J. Smoltz	3.15	179	47	27	.635	105	698	6	2	44	777.0	727	272	287	69	176	14	61	23	3,184	23	8.08	2.04	3.97	0.80	21.9	5.5	1.16	.295	3.32	73	3.20	73	8.42	101.1
9	Tim Lincecum T. Lincecum	3.16	58	25	10	.714	57	415	2	1	0	373.1	304	131	142	23	149	8	0	6	1,546	27	10.00	3.59	2.79	0.55	26.8	9.6	1.21	.295	3.42	73	3.00	70	7.33	54.3
10	Justin Masterson J. Masterson	3.16	36	6	5	.545	9	68	0	0	0	88.1	68	31	31	10	40	8	6	3	365	1	6.93	4.08	1.70	1.02	18.6	11.0	1.22	.243	3.16	70	4.69	112	6.93	-5.2
11	Roy Oswalt R. Oswalt	3.22	169	86	47	.647	166	875	12	5	0	1120.0	1,116	401	430	90	255	42	1	20	4,653	13	7.03	2.05	3.43	0.72	18.8	5.5	1.22	.303	3.46	75	3.38	76	8.97	130.3
12	Roy Halladay R. Halladay	3.23	137	72	35	.673	136	680	26	6	0	966.0	918	347	376	76	178	28	0	14	3,904	15	6.34	1.66	3.82	0.71	17.4	4.6	1.13	.286	3.50	71	3.38	75	8.55	116.6
13	Ben Sheets B. Sheets	3.24	128	53	44	.546	128	785	15	3	0	839.1	767	302	334	87	152	10	0	7	3,404	30	8.42	1.63	5.16	0.93	23.1	4.5	1.09	.287	3.58	75	3.15	72	8.22	115.9
14	Brandon Webb B. Webb	3.30	169	77	53	.592	169	891	14	7	0	1135.0	1,054	416	486	78	365	36	0	30	4,745	47	7.07	2.89	2.44	0.62	18.8	7.7	1.25	.289	3.85	72	3.49	77	8.36	127.1
15	Chad Billingsley C. Billingsley	3.33	96	35	19	.648	68	401	2	1	0	437.2	411	162	175	36	202	14	7	12	1,885	20	8.25	4.15	1.99	0.74	21.3	10.7	1.40	.304	3.60	78	3.88	89	8.45	24
16	Salomon Torres S. Torres	3.34	383	24	27	.471	0	285	0	0	55	412.2	393	153	178	32	146	25	150	27	1,754	18	6.22	3.18	1.95	0.70	16.2	8.3	1.31	.285	3.88	78	3.97	92	8.57	16.8
17	CC Sabathia	3.40	158	74	48	.607	158	932	22	9	0	1071.1	1,004	405	444	95	274	36	0	9	4,410	14	7.83	2.30	3.40	0.80	21.1	6.2	1.19	.296	3.73	78	3.40	79	8.43	111
18	Cole Hamels C. Hamels	3.43	84	38	23	.623	84	518	4	2	0	543.0	473	207	227	72	144	7	0	15	2,215	10	8.59	2.39	3.60	1.19	23.4	6.5	1.14	.272	3.76	77	3.81	85	7.84	41.4
19	Carlos Zambrano C. Zambrano	3.45	161	78	40	.661	161	907	5	2	0	1052.0	865	403	437	96	455	57	0	16	4,434	29	7.76	3.89	1.99	0.82	20.5	10.3	1.25	.263	3.74	77	4.03	90	7.40	51.7
20	Adam Wainwright A. Wainwright	3.48	115	27	16	.628	52	299	2	0	3	411.0	400	159	173	32	127	16	11	7	1,744	12	6.55	2.78	2.35	0.70	17.1	7.3	1.28	.290	3.79	82	3.78	87	8.76	26.2
21	Ryan Dempster R. Dempster	3.59	259	26	26	.500	39	416	1	0	87	461.0	409	184	202	32	204	17	183	15	1,974	18	8.12	3.98	2.04	0.62	21.1	10.3	1.33	.289	3.94	79	3.65	82	7.98	40.2
22	Kelvim Escobar K. Escobar	3.60	109	43	35	.551	100	561	4	1	1	653.0	611	261	284	53	213	16	2	7	2,721	29	7.73	2.94	2.63	0.73	20.6	7.8	1.26	.297	3.91	80	3.51	80	8.42	65.7
23	Scott Kazmir S. Kazmir	3.61	125	47	37	.560	124	783	1	1	0	723.0	656	290	323	72	332	25	0	9	3,108	31	9.75	4.13	2.36	0.90	25.2	10.7	1.37	.308	4.02	83	3.73	85	8.17	51.8
24	Dan Haren D. Haren	3.61	149	62	45	.579	140	769	6	1	0	924.2	899	371	410	104	210	27	2	18	3,838	38	7.48	2.04	3.66	1.01	20.0	5.5	1.20	.291	3.99	83	3.69	84	8.75	72.7
25	John Lackey J. Lackey	3.66	156	72	43	.626	155	842	10	5	0	1012.1	1,006	412	449	93	295	50	0	14	4,273	59	7.49	2.62	2.85	0.83	19.7	6.9	1.29	.305	3.99	83	3.66	84	8.94	79.2