Dan Quisenberry has the lowest career ERA for the Royals, with an ERA of 2.55.

Interpreted as:

best all-time era with a minimum of 750 IP by a player for the royals

	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	Dan Quisenberry D. Quisenberry	2.55	920.1	573	51	44	.537	0	321	0	0	238	919	261	293	52	139	7	503	58	3,725	4	3.14	1.36	2.31	0.51	8.6	3.7	1.15	.270	2.87	62	3.24	81	8.99	75.8
2	Jeff Montgomery J. Montgomery	3.20	849.1	686	44	50	.468	0	720	0	0	304	760	302	332	79	287	26	543	39	3,548	32	7.63	3.04	2.51	0.84	20.3	8.1	1.23	.280	3.52	72	3.56	83	8.05	63.7
3	Bret Saberhagen B. Saberhagen	3.21	1660.1	252	110	78	.585	226	1,093	64	14	1	1,551	593	650	126	331	27	13	25	6,725	41	5.92	1.79	3.30	0.68	16.3	4.9	1.13	.277	3.52	78	3.09	78	8.41	158.1
4	Al Fitzmorris A. Fitzmorris	3.46	1098.0	243	70	48	.593	136	391	35	11	7	1,075	422	467	66	359	9	38	38	4,591	56	3.20	2.94	1.09	0.54	8.5	7.8	1.31	.268	3.83	95	3.63	100	8.81	-3
5	Marty Pattin M. Pattin	3.48	825.2	244	43	39	.524	63	370	18	2	21	801	319	369	74	217	14	92	36	3,447	12	4.03	2.37	1.71	0.81	10.7	6.3	1.23	.262	4.02	89	3.75	99	8.73	0.7
6	Kevin Appier K. Appier	3.49	1843.2	287	115	92	.556	275	1,458	32	10	0	1,671	714	771	138	634	39	2	30	7,688	72	7.12	3.09	2.30	0.67	19.0	8.2	1.25	.283	3.76	77	3.48	80	8.16	184.1
7	Dick Drago D. Drago	3.52	1134.0	182	61	70	.466	160	577	53	10	1	1,162	444	493	91	310	31	14	26	4,738	16	4.58	2.46	1.86	0.72	12.2	6.5	1.30	.287	3.91	99	3.43	94	9.22	29
8	Charlie Leibrandt C. Leibrandt	3.60	1257.0	194	76	61	.555	187	618	34	10	0	1,294	503	563	102	359	16	3	14	5,308	39	4.42	2.57	1.72	0.73	11.6	6.8	1.32	.283	4.03	87	3.73	94	9.26	36.4
9	Dennis Leonard D. Leonard	3.70	2187.0	312	144	106	.576	302	1,323	103	23	1	2,137	898	1,008	202	622	52	3	39	9,149	73	5.44	2.56	2.13	0.83	14.5	6.8	1.26	.278	4.15	93	3.59	93	8.79	62.5
10	Steve Busby S. Busby	3.72	1060.2	167	70	54	.565	150	659	53	7	0	1,003	438	483	73	433	25	8	22	4,505	28	5.59	3.67	1.52	0.62	14.6	9.6	1.35	.281	4.10	97	3.53	94	8.51	22
11	Larry Gura L. Gura	3.72	1701.1	310	111	78	.587	219	633	61	14	12	1,628	704	792	166	503	40	37	31	7,108	24	3.35	2.66	1.26	0.88	8.9	7.1	1.25	.254	4.19	93	4.18	107	8.61	-54.5
12	Bud Black B. Black	3.73	977.2	216	56	57	.496	128	508	16	3	10	942	405	457	100	289	29	37	22	4,109	27	4.68	2.66	1.76	0.92	12.4	7.0	1.26	.265	4.21	90	4.01	100	8.67	-0.1
13	Paul Splittorff P. Splittorff	3.81	2554.2	429	166	143	.537	392	1,057	88	17	1	2,644	1,082	1,243	192	780	34	13	41	10,829	41	3.72	2.75	1.36	0.68	9.8	7.2	1.34	.280	4.38	99	3.72	99	9.31	11
14	Mark Gubicza M. Gubicza	3.91	2218.2	382	132	135	.494	327	1,366	42	16	2	2,226	965	1,050	153	783	58	14	39	9,457	107	5.54	3.18	1.74	0.62	14.4	8.3	1.36	.292	4.26	92	3.66	88	9.03	116
15	Zack Greinke Z. Greinke	3.93	1387.1	266	66	91	.420	222	1,101	12	3	1	1,436	606	656	151	330	46	8	12	5,826	34	7.14	2.14	3.34	0.98	18.9	5.7	1.27	.306	4.26	89	3.75	88	9.32	83
16	Danny Duffy D. Duffy	3.95	1172.1	234	68	68	.500	204	1,048	1	0	1	1,111	514	545	144	432	45	7	6	4,974	52	8.05	3.32	2.43	1.11	21.1	8.7	1.32	.293	4.18	92	4.17	101	8.53	-5.8
17	Tom Gordon T. Gordon	4.02	1149.2	274	79	71	.527	144	999	12	2	3	1,040	514	572	91	587	20	58	27	4,971	71	7.82	4.60	1.70	0.71	20.1	11.8	1.42	.290	4.48	94	3.79	92	8.14	41.3
18	Jeff Suppan J. Suppan	4.73	864.2	138	39	51	.433	133	472	11	3	0	927	454	489	123	289	29	2	13	3,739	28	4.91	3.01	1.63	1.28	12.6	7.7	1.41	.285	5.09	96	4.92	104	9.65	-17.3
19	Luke Hochevar L. Hochevar	4.98	929.1	279	46	65	.414	128	702	5	2	3	946	514	550	116	299	45	40	10	3,963	41	6.80	2.90	2.35	1.12	17.7	7.5	1.34	.296	5.33	117	4.30	104	9.16	-18.4