Dave Stieb has the best career ERA for the Blue Jays, with an ERA of 3.42.

Interpreted as:

best blue jays with a minimum of 750 IP by a player pitchers vs left batters

	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 Stieb D. Stieb	3.42	2873.0	439	175	134	.566	408	1,658	103	30	3	2,545	1,091	1,208	224	1,020	129	14	36	11,965	51	5.19	3.20	1.63	0.70	13.9	8.5	1.24	.260	3.78	82	3.81	93	7.97	87.3
2	Jimmy Key J. Key	3.42	1695.2	317	116	81	.589	250	944	28	10	10	1,624	645	710	165	404	24	24	25	6,983	31	5.01	2.14	2.34	0.88	13.5	5.8	1.20	.268	3.77	83	3.69	90	8.62	75.9
3	Roy Halladay R. Halladay	3.43	2046.2	313	148	76	.661	287	1,495	49	15	1	1,997	780	870	172	455	56	6	22	8,433	43	6.57	2.00	3.29	0.76	17.7	5.4	1.20	.292	3.83	74	3.46	76	8.78	235.2
4	Doyle Alexander D. Alexander	3.56	750.0	106	46	26	.639	103	392	25	3	0	752	297	315	81	172	14	2	3	3,103	16	4.70	2.06	2.28	0.97	12.6	5.5	1.23	.275	3.78	85	3.83	94	9.02	20.4
5	Marcus Stroman M. Stroman	3.76	789.2	135	47	45	.511	129	635	3	1	1	788	330	365	70	221	16	1	2	3,288	30	7.24	2.52	2.87	0.80	19.3	6.7	1.28	.306	4.16	89	3.60	84	8.98	59.4
6	John Cerutti J. Cerutti	3.87	772.1	191	46	37	.554	108	369	7	2	2	800	332	378	110	254	16	23	18	3,279	30	4.30	2.96	1.45	1.28	11.3	7.7	1.36	.273	4.40	94	4.73	116	9.32	-56.4
7	R.A. Dickey	4.05	824.1	131	49	52	.485	130	602	6	1	0	762	371	408	114	269	41	1	3	3,469	26	6.57	2.94	2.24	1.24	17.4	7.8	1.25	.265	4.45	100	4.57	114	8.32	-49.7
8	David Wells D. Wells	4.06	1148.2	306	84	55	.604	138	784	18	2	13	1,171	518	566	126	294	28	65	28	4,821	46	6.14	2.30	2.67	0.99	16.3	6.1	1.28	.291	4.43	92	3.83	89	9.17	65.3
9	Juan Guzman J. Guzman	4.07	1215.2	195	76	62	.551	195	1,030	15	2	0	1,099	550	612	115	546	29	0	15	5,209	88	7.63	4.04	1.89	0.85	19.8	10.5	1.35	.282	4.53	90	3.97	88	8.14	69.9
10	José Berríos J. Berríos	4.09	790.1	139	53	39	.576	138	702	1	0	0	764	359	380	119	220	47	0	6	3,310	9	7.99	2.51	3.19	1.36	21.2	6.6	1.25	.290	4.33	101	4.36	105	8.70	-18
11	Jim Clancy J. Clancy	4.10	2204.2	352	128	140	.478	345	1,237	73	11	1	2,185	1,005	1,104	219	814	28	5	17	9,397	82	5.05	3.32	1.52	0.89	13.2	8.7	1.36	.277	4.51	98	4.04	99	8.92	12.6
12	Luis Leal L. Leal	4.14	946.0	165	51	58	.468	151	491	27	3	1	968	435	476	101	320	22	6	24	4,057	23	4.67	3.04	1.53	0.96	12.1	7.9	1.36	.278	4.53	99	4.15	102	9.21	-7.8
13	Ricky Romero R. Romero	4.16	801.1	129	51	45	.531	127	622	8	3	0	766	370	402	82	354	43	1	6	3,439	42	6.99	3.98	1.76	0.92	18.1	10.3	1.40	.293	4.51	98	4.33	102	8.60	-7.4
14	Pat Hentgen P. Hentgen	4.28	1636.0	270	107	85	.557	238	1,028	31	9	0	1,677	778	850	207	599	41	13	21	7,048	56	5.66	3.30	1.72	1.14	14.6	8.5	1.39	.284	4.68	92	4.65	101	9.23	-3.4
15	Todd Stottlemyre T. Stottlemyre	4.39	1139.0	206	69	70	.496	175	662	15	4	1	1,182	555	597	115	414	49	11	27	4,921	30	5.23	3.27	1.60	0.91	13.5	8.4	1.40	.290	4.72	106	4.23	102	9.34	-6.5
16	Kelvim Escobar K. Escobar	4.58	849.0	301	58	55	.513	101	744	6	3	58	846	432	469	84	394	30	130	21	3,739	25	7.89	4.18	1.89	0.89	19.9	10.5	1.46	.306	4.97	96	4.11	89	8.97	48.3
17	Chris Carpenter C. Carpenter	4.83	870.2	152	49	50	.495	135	612	12	5	0	984	467	520	111	331	35	6	8	3,831	32	6.33	3.42	1.85	1.15	16.0	8.6	1.51	.318	5.38	102	4.60	100	10.17	-0.1