Zack Greinke had the lowest ERA in 2015, with an ERA of 1.66.

Interpreted as:

best with a minimum of 1 IP per team game pitchers in 2015

	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	Zack Greinke Z. Greinke	1.66	2015	LAD	32	19	3	.864	32	200	1	0	0	222.2	148	41	43	14	40	5	0	1	843	7	8.08	1.62	5.00	0.57	23.7	4.7	0.84	.229	1.74	44	2.75	73	5.98	26.2
2	Jake Arrieta J. Arrieta	1.77	2015	CHC	33	22	6	.786	33	236	4	3	0	229.0	150	45	52	10	48	6	0	2	870	6	9.28	1.89	4.92	0.39	27.1	5.5	0.86	.246	2.04	45	2.34	60	5.90	39
3	Clayton Kershaw C. Kershaw	2.13	2015	LAD	33	16	7	.696	33	301	4	3	0	232.2	163	55	62	15	42	5	0	1	890	9	11.64	1.62	7.17	0.58	33.8	4.7	0.88	.281	2.40	57	1.98	52	6.31	47.7
4	David Price D. Price	2.45	2015	TOT	32	18	5	.783	32	225	3	1	0	220.1	190	60	70	17	47	3	0	2	888	4	9.19	1.92	4.79	0.69	25.3	5.3	1.08	.290	2.86	60	2.77	67	7.76	32.3
5	Dallas Keuchel D. Keuchel	2.48	2015	HOU	33	20	8	.714	33	216	3	2	0	232.0	185	64	68	17	51	2	0	0	911	9	8.38	1.98	4.24	0.66	23.7	5.6	1.02	.269	2.64	64	2.90	73	7.18	28.3
6	Jacob deGrom J. deGrom	2.54	2015	NYM	30	14	8	.636	30	205	0	0	0	191.0	149	54	59	16	38	2	0	2	751	6	9.66	1.79	5.39	0.75	27.3	5.1	0.98	.271	2.78	69	2.70	70	7.02	25
7	Gerrit Cole G. Cole	2.60	2015	PIT	32	19	8	.704	32	202	0	0	0	208.0	183	60	71	11	44	10	0	1	832	7	8.74	1.90	4.59	0.48	24.3	5.3	1.09	.304	3.07	68	2.65	70	7.92	26.9
8	Matt Harvey M. Harvey	2.71	2015	NYM	29	13	8	.619	29	188	0	0	0	189.1	156	57	62	18	37	5	0	2	755	4	8.94	1.76	5.08	0.86	24.9	4.9	1.02	.272	2.95	73	3.04	79	7.42	17.5
9	Sonny Gray S. Gray	2.73	2015	OAK	31	14	7	.667	31	169	3	2	0	208.0	166	63	71	17	59	2	0	0	831	13	7.31	2.55	2.86	0.74	20.3	7.1	1.08	.255	3.07	69	3.44	87	7.18	11.9
10	John Lackey J. Lackey	2.77	2015	STL	33	13	10	.565	33	175	1	0	0	218.0	211	67	71	21	53	4	0	5	896	5	7.22	2.19	3.30	0.87	19.5	5.9	1.21	.295	2.93	73	3.56	93	8.71	6.7
11	Max Scherzer M. Scherzer	2.79	2015	WSH	33	14	12	.538	33	276	4	3	0	228.2	176	71	74	27	34	5	0	2	899	10	10.86	1.34	8.12	1.06	30.7	3.8	0.92	.268	2.91	71	2.76	72	6.93	27.6
12	Madison Bumgarner M. Bumgarner	2.93	2015	SFG	32	18	9	.667	32	234	4	2	0	218.1	181	71	73	21	39	7	0	2	869	1	9.65	1.61	6.00	0.87	26.9	4.5	1.01	.282	3.01	78	2.87	78	7.46	20.4
13	Carlos Martinez C. Martinez	3.01	2015	STL	31	14	7	.667	29	184	0	0	0	179.2	168	60	65	13	63	8	1	5	755	8	9.22	3.16	2.92	0.65	24.4	8.3	1.29	.318	3.26	79	3.20	84	8.42	12.7
14	Shelby Miller S. Miller	3.02	2015	ATL	33	6	17	.261	33	171	2	2	0	205.1	183	69	82	13	73	6	0	8	860	5	7.50	3.20	2.34	0.57	19.9	8.5	1.25	.285	3.59	78	3.44	91	8.02	7.3
15	Lance Lynn L. Lynn	3.03	2015	STL	31	12	11	.522	31	167	0	0	0	175.1	172	59	66	13	68	5	0	5	751	2	8.57	3.49	2.46	0.67	22.2	9.1	1.37	.319	3.39	80	3.43	90	8.83	7.8
16	Scott Kazmir S. Kazmir	3.10	2015	TOT	31	7	11	.389	31	155	0	0	0	183.0	162	63	77	20	59	9	0	0	763	5	7.62	2.90	2.63	0.98	20.3	7.7	1.21	.273	3.79	79	3.97	100	7.97	0
17	Marco Estrada M. Estrada	3.13	2015	TOR	34	13	8	.619	28	131	0	0	0	181.0	134	63	67	24	55	5	3	2	725	2	6.51	2.73	2.38	1.19	18.1	7.6	1.04	.216	3.33	77	4.40	108	6.66	-6.4
18	A.J. Burnett	3.18	2015	PIT	26	9	7	.563	26	143	0	0	0	164.0	174	58	64	11	49	11	0	2	699	6	7.85	2.69	2.92	0.60	20.5	7.0	1.36	.336	3.51	83	3.35	88	9.55	8.2
19	Chris Archer C. Archer	3.23	2015	TBR	34	12	13	.480	34	252	1	1	0	212.0	175	76	85	19	66	3	0	0	868	13	10.70	2.80	3.82	0.81	29.0	7.6	1.14	.295	3.61	83	2.89	73	7.43	25.4
20	Tyson Ross T. Ross	3.26	2015	SDP	33	10	12	.455	33	212	1	0	0	196.0	172	71	78	9	84	8	0	3	823	14	9.73	3.86	2.52	0.41	25.8	10.2	1.31	.320	3.58	88	2.97	78	7.90	18.3
21	Jon Lester J. Lester	3.34	2015	CHC	32	11	12	.478	32	207	1	0	0	205.0	183	76	83	16	47	7	0	0	828	8	9.09	2.06	4.40	0.70	25.0	5.7	1.12	.303	3.64	85	2.91	75	8.03	21.9
22	Wei-Yin Chen W. Chen	3.34	2015	BAL	31	11	8	.579	31	153	0	0	0	191.1	192	71	78	28	41	5	0	0	792	3	7.20	1.93	3.73	1.32	19.3	5.2	1.22	.290	3.67	83	4.15	100	9.03	0.3
23	Jake Odorizzi J. Odorizzi	3.35	2015	TBR	28	9	9	.500	28	150	0	0	0	169.1	149	63	65	18	46	3	0	0	700	5	7.97	2.44	3.26	0.96	21.4	6.6	1.15	.271	3.45	86	3.61	91	7.92	6.6
24	Jose Quintana J. Quintana	3.36	2015	CWS	32	9	10	.474	32	177	1	1	0	206.1	218	77	81	16	44	8	0	4	862	5	7.72	1.92	4.02	0.70	20.5	5.1	1.27	.327	3.53	85	3.18	77	9.51	21.3
25	Francisco Liriano F. Liriano	3.38	2015	PIT	31	12	7	.632	31	205	0	0	0	186.2	155	70	75	15	70	5	0	1	773	10	9.88	3.38	2.93	0.72	26.5	9.1	1.21	.293	3.62	88	3.18	84	7.47	12.9