Zack Wheeler has the best career ERA by an active pitcher in the postseason when pitching at least 47 innings, with an ERA of 2.18.

Interpreted as:

best era postseason active player 47 or more ip

	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	H/9
1	Zack Wheeler Z. Wheeler	2.18	70.1	12	4	3	.571	11	77	0	0	0	37	17	19	5	14	5	0	0	264	1	9.85	1.79	5.50	0.64	29.2	5.3	0.73	.196	2.43	4.73
2	Kenley Jansen K. Jansen	2.20	65.1	59	3	2	.600	0	94	0	0	20	34	16	18	7	18	3	47	3	250	0	12.95	2.48	5.22	0.96	37.6	7.2	0.80	.211	2.48	4.68
3	Aroldis Chapman A. Chapman	2.26	51.2	46	3	4	.429	0	73	0	0	11	39	13	16	4	21	3	29	1	213	3	12.72	3.66	3.48	0.70	34.3	9.9	1.16	.313	2.79	6.79
4	Yoshinobu Yamamoto Y. Yamamoto	2.47	47.1	8	5	1	.833	8	41	2	0	0	29	13	15	5	10	3	0	0	185	1	7.80	1.90	4.10	0.95	22.2	5.4	0.82	.190	2.85	5.51
5	Gerrit Cole G. Cole	2.77	133.1	22	11	6	.647	22	156	0	0	0	100	41	50	19	36	3	0	1	537	1	10.53	2.43	4.33	1.28	29.1	6.7	1.02	.251	3.38	6.75
6	Blake Snell B. Snell	3.01	74.2	16	7	4	.636	14	93	0	0	1	52	25	25	8	31	1	1	0	297	3	11.21	3.74	3.00	0.96	31.3	10.4	1.11	.268	3.01	6.27
7	Walker Buehler W. Buehler	3.04	94.2	19	4	4	.500	18	114	0	0	1	73	32	34	9	36	2	1	2	388	3	10.84	3.42	3.17	0.86	29.4	9.3	1.15	.282	3.23	6.94
8	Nathan Eovaldi N. Eovaldi	3.05	79.2	17	9	3	.750	12	82	0	0	0	65	27	28	6	18	1	1	3	325	0	9.26	2.03	4.56	0.68	25.2	5.5	1.04	.271	3.16	7.34
9	Kyle Hendricks K. Hendricks	3.12	57.2	12	2	4	.333	11	51	0	0	0	53	20	22	10	16	3	0	1	242	0	7.96	2.50	3.19	1.56	21.1	6.6	1.20	.265	3.43	8.27
10	David Robertson D. Robertson	3.40	47.2	43	6	1	.857	0	57	0	0	1	38	18	18	6	16	2	11	3	196	3	10.76	3.02	3.56	1.13	29.1	8.2	1.13	.278	3.40	7.17
11	Lance McCullers Jr. L. McCullers Jr.	3.47	72.2	19	2	3	.400	12	80	0	0	1	60	28	34	15	22	10	1	0	301	3	9.91	2.72	3.64	1.86	26.6	7.3	1.13	.259	4.21	7.43
12	Justin Verlander J. Verlander	3.58	226.0	38	17	12	.586	37	244	2	1	0	179	90	93	32	74	5	0	0	920	8	9.72	2.95	3.30	1.27	26.5	8.0	1.12	.260	3.70	7.13
13	Charlie Morton C. Morton	3.60	80.0	18	7	5	.583	17	92	0	0	0	67	32	34	8	33	7	1	0	343	5	10.35	3.71	2.79	0.90	26.8	9.6	1.25	.291	3.83	7.54
14	Max Scherzer M. Scherzer	3.75	148.2	31	8	8	.500	26	176	0	0	1	112	62	65	21	60	9	1	4	616	8	10.65	3.63	2.93	1.27	28.6	9.7	1.16	.260	3.93	6.78
15	Kevin Gausman K. Gausman	3.75	50.1	13	2	4	.333	7	48	0	0	0	32	21	21	7	20	0	2	2	199	0	8.58	3.58	2.40	1.25	24.1	10.1	1.03	.202	3.75	5.72
16	Aaron Nola A. Nola	3.88	55.2	11	5	4	.556	11	61	0	0	0	53	24	25	8	11	3	0	0	231	0	9.86	1.78	5.55	1.29	26.4	4.8	1.15	.304	4.04	8.57
17	Yu Darvish Y. Darvish	3.96	72.2	14	5	8	.385	14	62	0	0	0	62	32	34	18	15	8	0	1	296	1	7.68	1.86	4.13	2.23	20.9	5.1	1.06	.228	4.21	7.68
18	Framber Valdez F. Valdez	4.34	85.0	17	7	6	.538	16	95	0	0	0	82	41	45	14	34	4	1	0	360	0	10.06	3.60	2.79	1.48	26.4	9.4	1.36	.319	4.76	8.68
19	Tyler Glasnow T. Glasnow	4.58	59.0	13	2	6	.250	12	79	0	0	0	50	30	31	10	33	0	0	0	258	7	12.05	5.03	2.39	1.53	30.6	12.8	1.41	.294	4.73	7.63
20	Luis Severino L. Severino	4.62	60.1	14	2	5	.286	13	57	0	0	0	62	31	34	10	27	2	0	0	271	0	8.50	4.03	2.11	1.49	21.0	10.0	1.48	.297	5.07	9.25
21	Clayton Kershaw C. Kershaw	4.63	196.1	40	13	13	.500	32	213	0	0	1	171	101	107	32	54	4	2	6	802	11	9.76	2.48	3.94	1.47	26.6	6.7	1.15	.279	4.90	7.84
22	Jack Flaherty J. Flaherty	5.05	57.0	13	2	6	.250	11	58	0	0	0	56	32	33	9	26	2	0	0	247	3	9.16	4.11	2.23	1.42	23.5	10.5	1.44	.309	5.21	8.84
23	Max Fried M. Fried	5.31	76.1	22	2	6	.250	14	73	0	0	0	94	45	47	11	23	2	0	0	343	4	8.61	2.71	3.17	1.30	21.3	6.7	1.53	.355	5.54	11.08