Dick Ellsworth lost the most games in 1966, with 22 games.

	NAME	L	SEASON	TM	W	L%	G	W%	GS	ERA	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	Dick Ellsworth D. Ellsworth	22	1966	CHC	8	.733	38	.267	37	3.98	144	9	0	0	269.1	321	119	150	28	51	5	0	5	1,169	5	4.81	1.70	2.82	0.94	12.3	4.4	1.38	.311	5.01	105	3.46	94	10.73	6.4
2	Mel Stottlemyre M. Stottlemyre	20	1966	NYY	12	.625	37	.375	35	3.80	146	9	3	1	251.0	239	106	116	18	82	1	2	7	1,042	8	5.24	2.94	1.78	0.65	14.0	7.9	1.28	.278	4.16	113	3.31	95	8.57	4.5
3	Sammy Ellis S. Ellis	19	1966	CIN	12	.613	41	.387	36	5.29	154	7	0	0	221.0	226	130	135	35	78	3	2	8	960	9	6.27	3.18	1.97	1.43	16.0	8.1	1.38	.277	5.50	137	4.32	116	9.20	-12.7
4	Dean Chance D. Chance	17	1966	CAL	12	.586	41	.414	37	3.08	180	11	2	1	259.2	206	89	113	18	114	7	2	9	1,067	8	6.24	3.95	1.58	0.62	16.9	10.7	1.23	.251	3.92	94	3.47	102	7.14	-2.2
5	Don Drysdale D. Drysdale	16	1966	LAD	13	.552	40	.448	40	3.42	177	11	3	0	273.2	279	104	114	21	45	17	0	8	1,135	7	5.82	1.48	3.93	0.69	15.6	4.0	1.18	.295	3.75	104	2.94	93	9.18	6.5
6	Ken Holtzman K. Holtzman	16	1966	CHC	11	.593	34	.407	33	3.79	171	9	0	0	220.2	194	93	104	27	68	4	0	6	912	8	6.97	2.77	2.51	1.10	18.8	7.5	1.19	.260	4.24	100	3.57	98	7.91	2.6
7	Gary Bell G. Bell	15	1966	CLE	14	.517	40	.483	37	3.22	194	12	0	0	254.1	211	91	102	19	79	4	1	3	1,028	9	6.87	2.80	2.46	0.67	18.9	7.7	1.14	.262	3.61	94	2.98	84	7.47	16.3
8	Nelson Briles N. Briles	15	1966	STL	4	.789	49	.211	17	3.21	100	0	0	6	154.0	162	55	65	14	54	7	17	11	654	3	5.84	3.16	1.85	0.82	15.3	8.3	1.40	.309	3.80	90	3.63	105	9.47	-3.1
9	Al Jackson A. Jackson	15	1966	STL	13	.536	36	.464	30	2.51	90	11	3	0	232.2	222	65	82	18	45	3	2	10	950	4	3.48	1.74	2.00	0.70	9.5	4.7	1.15	.257	3.17	70	3.41	99	8.59	1.1
10	Larry Jackson L. Jackson	15	1966	TOT	15	.500	38	.500	35	3.32	112	12	5	0	255.0	257	94	106	25	62	5	1	5	1,057	3	3.95	2.19	1.81	0.88	10.6	5.9	1.25	.272	3.74	92	3.74	108	9.07	-7.9
11	Jim Bunning J. Bunning	14	1966	PHI	19	.424	43	.576	41	2.41	252	16	5	1	314.0	260	84	91	26	55	19	2	8	1,254	5	7.22	1.58	4.58	0.75	20.1	4.4	1.00	.259	2.61	67	2.73	79	7.45	25.2
12	Jack Fisher J. Fisher	14	1966	NYM	11	.560	38	.440	33	3.68	127	10	2	0	230.0	229	94	108	26	54	8	4	2	960	12	4.97	2.11	2.35	1.02	13.2	5.6	1.23	.272	4.23	103	3.73	108	8.96	-7.2
13	Dave Giusti D. Giusti	14	1966	HOU	15	.483	34	.517	33	4.20	131	9	4	0	210.0	215	98	112	23	54	5	0	3	892	14	5.61	2.31	2.43	0.99	14.7	6.1	1.28	.283	4.80	120	3.57	106	9.21	-4.9
14	Mickey Lolich M. Lolich	14	1966	DET	14	.500	40	.500	33	4.77	173	5	1	2	203.2	204	108	119	24	83	6	4	8	894	11	7.64	3.67	2.08	1.06	19.4	9.3	1.41	.296	5.26	138	3.70	103	9.01	-2.3
15	Marcelino Lopez M. Lopez	14	1966	CAL	7	.667	37	.333	32	3.93	132	6	2	1	199.0	188	87	95	20	68	9	2	2	842	12	5.97	3.08	1.94	0.90	15.7	8.1	1.29	.274	4.30	119	3.69	108	8.50	-6.9
16	Mike McCormick M. McCormick	14	1966	WSH	11	.560	41	.440	32	3.46	101	8	3	0	216.0	193	83	98	23	51	2	5	8	884	6	4.21	2.13	1.98	0.96	11.4	5.8	1.13	.240	4.08	102	3.74	106	8.04	-5.5
17	Denny McLain D. McLain	14	1966	DET	20	.412	38	.588	38	3.92	192	14	4	0	264.1	205	115	120	42	104	3	0	3	1,080	6	6.54	3.54	1.85	1.43	17.8	9.6	1.17	.221	4.09	113	4.38	122	6.98	-22.9
18	Jim Merritt J. Merritt	14	1966	MIN	7	.667	31	.333	18	3.38	124	5	1	3	144.0	112	54	57	17	33	0	5	3	570	4	7.75	2.06	3.76	1.06	21.8	5.8	1.01	.240	3.56	94	3.05	83	7.00	10.2
19	Claude Osteen C. Osteen	14	1966	LAD	17	.452	39	.548	38	2.85	137	8	3	0	240.1	238	76	92	6	65	2	1	13	1,005	5	5.13	2.43	2.11	0.22	13.6	6.5	1.26	.292	3.45	87	2.57	81	8.91	16.3
20	Pete Richert P. Richert	14	1966	WSH	14	.500	36	.500	34	3.37	195	7	0	0	245.2	196	92	106	36	69	1	0	6	993	4	7.14	2.53	2.83	1.32	19.6	6.9	1.08	.231	3.88	99	3.73	106	7.18	-5.9
21	Bob Shaw B. Shaw	14	1966	TOT	12	.538	39	.462	31	4.29	125	7	2	0	199.1	216	95	108	21	49	7	5	2	858	11	5.64	2.21	2.55	0.95	14.6	5.7	1.33	.297	4.88	120	3.51	101	9.75	-1.2
22	Bob Bruce B. Bruce	13	1966	HOU	3	.813	25	.188	23	5.34	71	1	0	0	129.2	160	77	83	16	29	8	0	4	574	1	4.93	2.01	2.45	1.11	12.4	5.1	1.46	.320	5.76	153	3.92	116	11.11	-8.2
23	George Brunet G. Brunet	13	1966	CAL	13	.500	41	.500	32	3.31	148	8	2	0	212.0	183	78	88	21	106	5	3	8	913	4	6.28	4.50	1.40	0.89	16.2	11.6	1.36	.256	3.74	100	4.02	118	7.77	-15.3
24	Mudcat Grant M. Grant	13	1966	MIN	13	.500	35	.500	35	3.25	110	10	3	0	249.0	248	90	104	23	49	6	0	2	1,031	5	3.98	1.77	2.24	0.83	10.7	4.8	1.19	.267	3.76	91	3.53	96	8.96	4.8
25	Jack Hamilton J. Hamilton	13	1966	NYM	6	.684	57	.316	13	3.93	93	3	1	13	148.2	138	65	89	13	88	5	29	4	662	18	5.63	5.33	1.06	0.79	14.0	13.3	1.52	.270	5.39	110	4.32	125	8.35	-14.5