Mark Eichhorn has the best ERA for the Blue Jays in a season, with an ERA of 1.72 in his rookie season in 1986.

Interpreted as:

blue jay pitcher with best season era with a minimum of 0.5 IP per team game

	NAME	ERA	SEASON	TM	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	Mark Eichhorn M. Eichhorn	1.72	1986	TOR	69	14	6	.700	0	166	0	0	10	157.0	105	30	32	8	45	7	38	14	612	2	9.52	2.58	3.69	0.46	27.1	7.4	0.96	.251	1.83	41	2.30	56	6.02	31.8
2	Tom Henke T. Henke	1.92	1989	TOR	64	8	3	.727	0	116	0	0	20	89.0	66	19	20	5	25	2	56	4	356	2	11.73	2.53	4.64	0.51	32.6	7.0	1.02	.293	2.02	49	1.79	46	6.67	20.5
3	Paul Quantrill P. Quantrill	1.94	1997	TOR	77	6	7	.462	0	56	0	0	5	88.0	103	19	25	5	17	1	29	3	373	1	5.73	1.74	3.29	0.51	15.0	4.6	1.36	.333	2.56	43	3.18	71	10.53	12.8
4	Duane Ward D. Ward	1.95	1992	TOR	79	7	4	.636	0	103	0	0	12	101.1	76	22	27	5	39	1	35	3	414	7	9.15	3.46	2.64	0.44	24.9	9.4	1.13	.267	2.40	49	2.57	64	6.75	16
5	Roger Clemens R. Clemens	2.05	1997	TOR	34	21	7	.750	34	292	9	3	0	264.0	204	60	65	9	68	12	0	1	1,044	4	9.95	2.32	4.29	0.31	28.0	6.5	1.03	.294	2.22	45	2.24	50	6.95	66.3
6	Alek Manoah A. Manoah	2.24	2022	TOR	31	16	7	.696	31	180	0	0	0	196.2	144	49	55	16	51	15	0	0	786	5	8.24	2.33	3.53	0.73	22.9	6.5	0.99	.244	2.52	58	3.34	83	6.59	14.7
7	Jerry Garvin J. Garvin	2.29	1980	TOR	61	4	7	.364	0	52	0	0	8	82.2	70	21	23	6	27	0	24	7	336	0	5.66	2.94	1.93	0.65	15.5	8.0	1.17	.255	2.50	55	3.41	83	7.62	6.4
8	David Wells D. Wells	2.40	1989	TOR	54	7	4	.636	0	78	0	0	2	86.1	66	23	25	5	28	0	19	7	352	6	8.13	2.92	2.79	0.52	22.2	8.0	1.09	.253	2.61	61	2.67	68	6.88	11.6
9	Roy Halladay R. Halladay	2.41	2005	TOR	19	12	4	.750	19	108	5	2	0	141.2	118	38	39	11	18	7	0	2	553	2	6.86	1.14	6.00	0.70	19.5	3.3	0.96	.262	2.48	54	3.02	69	7.50	21.4
10	Dave Stieb D. Stieb	2.48	1985	TOR	36	14	13	.519	36	167	8	2	0	265.0	206	73	89	22	96	9	0	3	1,087	4	5.67	3.26	1.74	0.75	15.4	8.8	1.14	.232	3.02	59	3.69	90	7.00	11.8
11	Tom Henke T. Henke	2.49	1987	TOR	72	0	6	.000	0	128	0	0	34	94.0	62	26	27	10	25	0	62	3	363	5	12.26	2.39	5.12	0.96	35.3	6.9	0.93	.260	2.59	55	2.32	53	5.94	22.1
12	Tony Castillo T. Castillo	2.51	1994	TOR	41	5	2	.714	0	43	0	0	1	68.0	66	19	22	7	28	3	8	1	291	0	5.69	3.71	1.54	0.93	14.8	9.6	1.38	.281	2.91	52	4.56	95	8.74	1.7
13	Roy Lee Jackson R. Lee Jackson	2.61	1981	TOR	39	1	2	.333	0	27	0	0	7	62.0	65	18	23	5	25	1	21	7	266	5	3.92	3.63	1.08	0.73	10.2	9.4	1.45	.288	3.34	67	4.03	105	9.44	-1.3
14	Juan Guzman J. Guzman	2.64	1992	TOR	28	16	5	.762	28	165	1	0	0	180.2	135	53	56	6	72	1	0	2	733	14	8.22	3.59	2.29	0.30	22.5	9.8	1.15	.264	2.79	66	2.59	65	6.73	28.1
15	Roger Clemens R. Clemens	2.65	1998	TOR	33	20	6	.769	33	271	5	3	0	234.2	169	69	78	11	88	7	0	0	961	6	10.39	3.38	3.08	0.42	28.2	9.2	1.10	.271	2.99	57	2.65	59	6.48	49.2
16	Hyun Jin Ryu H. Jin Ryu	2.69	2020	TOR	12	5	2	.714	12	72	0	0	0	67.0	60	20	22	6	17	1	0	0	275	1	9.67	2.28	4.24	0.81	26.2	6.2	1.15	.302	2.96	58	3.00	68	8.06	10.5
17	Jimmy Key J. Key	2.76	1987	TOR	36	17	8	.680	36	161	8	1	0	261.0	210	80	93	24	66	2	0	6	1,033	8	5.55	2.28	2.44	0.83	15.6	6.4	1.06	.238	3.21	61	3.60	82	7.24	23.6
18	Duane Ward D. Ward	2.77	1991	TOR	81	7	6	.538	0	132	0	0	23	107.1	80	33	36	3	33	2	46	3	428	6	11.07	2.77	4.00	0.25	30.8	7.7	1.05	.298	3.02	67	1.73	42	6.71	28.3
19	Roy Halladay R. Halladay	2.78	2008	TOR	34	20	11	.645	33	206	9	2	0	246.0	220	76	88	18	39	12	0	3	987	4	7.54	1.43	5.28	0.66	20.9	4.0	1.05	.284	3.22	64	3.02	69	8.05	36.3
20	Roy Halladay R. Halladay	2.79	2009	TOR	32	17	10	.630	32	208	9	4	0	239.0	234	74	82	22	35	5	0	0	963	2	7.83	1.32	5.94	0.83	21.6	3.6	1.13	.306	3.09	63	3.05	68	8.81	37.1
21	Dave Stieb D. Stieb	2.83	1984	TOR	35	16	8	.667	35	198	11	2	0	267.0	215	84	87	19	88	11	0	1	1,085	2	6.67	2.97	2.25	0.64	18.2	8.1	1.13	.255	2.93	68	3.32	82	7.25	21.8
22	Robbie Ray R. Ray	2.84	2021	TOR	32	13	7	.650	32	248	0	0	0	193.1	150	61	62	33	52	4	0	0	773	5	11.54	2.42	4.77	1.54	32.1	6.7	1.04	.268	2.89	63	3.68	87	6.98	11.8
23	Joey McLaughlin J. McLaughlin	2.85	1981	TOR	40	1	5	.167	0	38	0	0	10	60.0	55	19	24	2	21	0	26	2	249	1	5.70	3.15	1.81	0.30	15.3	8.4	1.27	.282	3.60	74	2.81	73	8.25	6.7
24	Ricky Romero R. Romero	2.92	2011	TOR	32	15	11	.577	32	178	4	2	0	225.0	176	73	85	26	80	14	0	2	917	9	7.12	3.20	2.23	1.04	19.4	8.7	1.14	.242	3.40	70	4.19	102	7.04	-1.6
25	Juan Guzman J. Guzman	2.93	1996	TOR	27	11	8	.579	27	165	4	1	0	187.2	158	61	68	20	53	7	0	3	756	7	7.91	2.54	3.11	0.96	21.8	7.0	1.12	.270	3.26	59	3.75	76	7.58	24.3