Zack Greinke had his highest ERA in a season in the month of April in 2023, with an ERA of 6.66.

Interpreted as:

zach greinke's worst era in a regular season in aprils

	NAME	ERA	SEASON	TM	G	W	L	W%	GS	SO	CG	SHO	IP	H	ER	R	HR	BB	HBP	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Zack Greinke Z. Greinke	6.66	2023	KCR	5	0	3	.000	5	18	0	0	25.2	32	19	20	7	5	0	0	112	0	6.31	1.75	3.60	2.45	16.1	4.5	1.44	.305	7.01	11.22
2	Zack Greinke Z. Greinke	5.50	2016	ARI	6	2	2	.500	6	32	0	0	37.2	47	23	23	5	8	0	0	166	0	7.65	1.91	4.00	1.19	19.3	4.8	1.46	.347	5.50	11.23
3	Zack Greinke Z. Greinke	5.04	2018	ARI	5	3	2	.600	5	33	0	0	30.1	30	17	17	5	4	2	0	124	0	9.79	1.19	8.25	1.48	26.6	3.2	1.12	.313	5.04	8.90
4	Zack Greinke Z. Greinke	3.94	2012	MIL	5	3	1	.750	5	30	0	0	29.2	32	13	13	1	9	0	0	125	2	9.10	2.73	3.33	0.30	24.0	7.2	1.38	.365	3.94	9.71
5	Zack Greinke Z. Greinke	3.65	2005	KCR	5	0	2	.000	5	14	0	0	24.2	28	10	13	2	5	3	0	113	1	5.11	1.82	2.80	0.73	12.4	4.4	1.34	.292	4.74	10.22
6	Zack Greinke Z. Greinke	3.51	2007	KCR	5	1	2	.333	5	16	0	0	25.2	30	10	11	1	9	2	1	112	0	5.61	3.16	1.78	0.35	14.3	8.0	1.52	.345	3.86	10.52
7	Zack Greinke Z. Greinke	3.44	2021	HOU	6	2	1	.667	6	27	0	0	36.2	36	14	14	5	6	1	0	147	2	6.63	1.47	4.50	1.23	18.4	4.1	1.15	.287	3.44	8.84
8	Zack Greinke Z. Greinke	3.19	2017	ARI	6	2	2	.500	6	40	1	0	36.2	37	13	13	5	8	0	0	152	1	9.82	1.96	5.00	1.23	26.3	5.3	1.23	.323	3.19	9.08
9	Zack Greinke Z. Greinke	2.86	2022	KCR	4	0	1	.000	4	6	0	0	22.0	21	7	7	1	3	2	0	87	1	2.45	1.23	2.00	0.41	6.9	3.4	1.09	.267	2.86	8.59
10	Zack Greinke Z. Greinke	2.56	2010	KCR	5	0	2	.000	5	27	0	0	31.2	28	9	12	3	7	3	0	131	0	7.67	1.99	3.86	0.85	20.6	5.3	1.11	.275	3.41	7.96
11	Zack Greinke Z. Greinke	2.04	2014	LAD	6	5	0	1.000	6	46	0	0	35.1	31	8	9	6	6	0	1	142	2	11.72	1.53	7.67	1.53	32.4	4.2	1.05	.298	2.29	7.90
12	Zack Greinke Z. Greinke	2.01	2019	ARI	6	5	0	1.000	6	43	0	0	40.1	27	9	10	4	6	0	0	149	0	9.60	1.34	7.17	0.89	28.9	4.0	0.82	.240	2.23	6.02
13	Zack Greinke Z. Greinke	1.93	2015	LAD	5	4	0	1.000	5	27	0	0	32.2	23	7	7	2	7	1	0	128	2	7.44	1.93	3.86	0.55	21.1	5.5	0.92	.231	1.93	6.34
14	Zack Greinke Z. Greinke	1.59	2013	LAD	2	1	0	1.000	2	10	0	0	11.1	7	2	2	0	1	1	0	42	1	7.94	0.79	10.00	0.00	23.8	2.4	0.71	.233	1.59	5.56
15	Zack Greinke Z. Greinke	1.25	2008	KCR	5	3	0	1.000	5	19	1	0	36.0	30	5	6	2	10	0	0	143	1	4.75	2.50	1.90	0.50	13.3	7.0	1.11	.250	1.50	7.50
16	Zack Greinke Z. Greinke	0.50	2009	KCR	5	5	0	1.000	5	44	2	1	36.0	24	2	3	0	8	1	0	138	1	11.00	2.00	5.50	0.00	31.9	5.8	0.89	.282	0.75	6.00