Dave Smith has the best career ERA for the Astros, with an ERA of 2.53.

Interpreted as:

astros era with a minimum of 750 IP leader all-time

	NAME	ERA	IP	G	W	L	W%	GS	SO	CG	SHO	SV	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	Dave Smith D. Smith	2.53	762.0	563	53	47	.530	1	529	0	0	199	646	214	254	28	260	12	400	57	3,145	27	6.25	3.07	2.03	0.33	16.8	8.3	1.19	.267	3.00	74	2.90	84	7.63	47.3
2	Justin Verlander J. Verlander	2.71	810.1	130	73	28	.723	130	962	3	2	0	589	244	261	106	155	31	0	0	3,166	16	10.68	1.72	6.21	1.18	30.4	4.9	0.92	.253	2.90	65	3.18	76	6.54	92.7
3	Nolan Ryan N. Ryan	3.13	1854.2	282	106	94	.530	282	1,866	38	13	0	1,441	645	739	111	796	44	0	31	7,716	104	9.05	3.86	2.34	0.54	24.2	10.3	1.21	.271	3.59	91	2.86	83	6.99	124.4
4	Don Wilson D. Wilson	3.15	1748.1	266	104	92	.531	245	1,283	78	20	2	1,479	611	698	119	640	47	10	32	7,305	77	6.60	3.29	2.00	0.61	17.6	8.8	1.21	.261	3.59	92	3.09	92	7.61	43.7
5	J.R. Richard	3.15	1606.0	238	107	71	.601	221	1,493	76	19	0	1,227	562	625	73	770	17	3	15	6,674	92	8.37	4.32	1.94	0.41	22.4	11.5	1.24	.267	3.50	92	2.85	82	6.88	114.7
6	Ken Forsch K. Forsch	3.18	1493.2	421	78	81	.491	153	815	36	9	50	1,439	528	587	96	428	26	171	58	6,213	36	4.91	2.58	1.90	0.58	13.1	6.9	1.25	.277	3.54	92	3.25	94	8.67	30.3
7	Danny Darwin D. Darwin	3.21	769.0	220	47	35	.573	81	543	10	1	12	694	274	299	66	201	24	52	37	3,171	8	6.36	2.35	2.70	0.77	17.1	6.3	1.16	.269	3.50	89	3.40	94	8.12	15.2
8	Joe Niekro J. Niekro	3.22	2270.0	397	144	116	.554	301	1,178	82	21	9	2,052	811	934	139	818	41	41	33	9,490	128	4.67	3.24	1.44	0.55	12.4	8.6	1.26	.262	3.70	95	3.59	104	8.14	-46
9	Roy Oswalt R. Oswalt	3.24	1932.1	303	143	82	.636	291	1,593	19	7	0	1,865	696	747	167	446	68	5	32	7,976	23	7.42	2.08	3.57	0.78	20.0	5.6	1.20	.298	3.48	76	3.35	77	8.69	217.7
10	Larry Dierker L. Dierker	3.28	2294.1	345	137	117	.539	320	1,487	106	25	1	2,090	837	927	177	695	48	9	43	9,492	102	5.83	2.73	2.14	0.69	15.7	7.3	1.21	.270	3.64	96	3.20	96	8.20	33.2
11	Mike Scott M. Scott	3.30	1704.0	263	110	81	.576	259	1,318	42	21	0	1,444	625	694	144	505	30	3	45	6,989	35	6.96	2.67	2.61	0.76	18.9	7.2	1.14	.260	3.67	94	3.26	93	7.63	45.3
12	Mark Portugal M. Portugal	3.34	782.1	135	52	30	.634	123	535	6	3	1	711	290	322	64	281	13	4	15	3,262	23	6.15	3.23	1.90	0.74	16.4	8.6	1.27	.273	3.70	93	3.67	102	8.18	-9.4
13	Framber Valdez F. Valdez	3.38	1073.2	187	80	52	.606	165	1,043	9	3	0	905	403	443	86	387	58	7	1	4,453	61	8.74	3.24	2.70	0.72	23.4	8.7	1.20	.284	3.71	82	3.51	84	7.59	77
14	Turk Farrell T. Farrell	3.42	1015.0	181	53	64	.453	132	694	41	5	8	947	386	432	95	212	14	29	21	4,148	15	6.15	1.88	3.27	0.84	16.7	5.1	1.14	.272	3.83	100	3.07	92	8.40	29.4
15	Mike Hampton M. Hampton	3.59	1138.0	216	76	50	.603	172	767	13	6	0	1,140	454	525	88	419	23	7	16	4,844	35	6.07	3.31	1.83	0.70	15.8	8.6	1.37	.297	4.15	89	3.94	96	9.02	21
16	Collin McHugh C. McHugh	3.63	753.1	195	58	35	.624	110	743	1	0	0	699	304	320	82	219	33	26	4	3,145	24	8.88	2.62	3.39	0.98	23.6	7.0	1.22	.298	3.82	90	3.59	88	8.35	42.2
17	Bob Knepper B. Knepper	3.66	1738.0	284	93	100	.482	267	946	41	18	1	1,748	706	812	148	521	27	5	40	7,315	36	4.90	2.70	1.82	0.77	12.9	7.1	1.31	.282	4.20	105	3.70	107	9.05	-56.1
18	Dallas Keuchel D. Keuchel	3.66	1189.1	192	76	63	.547	183	945	12	4	0	1,144	484	521	115	343	21	2	7	4,937	44	7.15	2.60	2.76	0.87	19.1	6.9	1.25	.293	3.94	92	3.71	92	8.66	45.3
19	Jim Deshaies J. Deshaies	3.67	1102.0	181	61	59	.508	178	731	14	6	0	960	449	479	113	423	17	0	36	4,599	16	5.97	3.45	1.73	0.92	15.9	9.2	1.25	.256	3.91	103	4.00	113	7.84	-64.1
20	Joaquin Andujar J. Andujar	3.67	860.0	202	44	53	.454	113	388	23	5	7	823	351	404	48	361	16	31	24	3,695	13	4.06	3.78	1.07	0.50	10.5	9.8	1.38	.269	4.23	108	3.83	110	8.61	-37.9
21	Dave Roberts D. Roberts	3.69	843.2	140	47	44	.516	121	403	34	11	4	889	346	373	55	257	9	9	17	3,604	20	4.30	2.74	1.57	0.59	11.2	7.1	1.36	.290	3.98	107	3.36	98	9.48	5.2
22	Lance McCullers Jr. L. McCullers Jr.	3.70	771.0	145	51	37	.580	139	857	1	0	0	662	317	343	66	334	45	2	4	3,278	48	10.00	3.90	2.57	0.77	26.1	10.2	1.29	.302	4.00	90	3.51	84	7.73	57.3
23	Bob Bruce B. Bruce	3.78	907.0	157	42	58	.420	138	609	24	6	0	918	381	425	69	242	40	4	18	3,851	29	6.04	2.40	2.52	0.68	15.8	6.3	1.28	.294	4.22	110	3.13	94	9.11	18.7
24	Darryl Kile D. Kile	3.79	1200.0	209	71	65	.522	182	973	16	6	0	1,128	505	580	89	562	72	7	27	5,241	58	7.30	4.22	1.73	0.67	18.6	10.7	1.41	.293	4.35	99	3.96	103	8.46	-14.6
25	Wade Miller W. Miller	3.87	768.0	127	58	39	.598	123	659	5	1	0	699	330	362	91	306	23	2	14	3,246	18	7.72	3.59	2.15	1.07	20.3	9.4	1.31	.281	4.24	87	4.14	94	8.19	23.8