Since 1998, Bartolo Colon has lost the most games, with 181 games.

Interpreted as:

MLB most regular-season losses by a player since 1998

	NAME	L	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	Bartolo Colon B. Colon	181	243	.427	546	.573	535	4.08	2,469	37	13	0	3367.2	3,486	1,525	1,653	427	903	61	2	46	14,228	40	6.60	2.41	2.73	1.14	17.4	6.3	1.30	.295	4.42	94	4.12	95	9.32	75.9
2	Livan Hernandez L. Hernandez	174	169	.507	501	.493	457	4.48	1,902	50	9	1	3089.2	3,441	1,538	1,647	357	1,026	75	17	85	13,398	41	5.54	2.99	1.85	1.04	14.2	7.7	1.45	.307	4.80	106	4.42	104	10.02	-52
3	CC Sabathia	161	251	.391	561	.609	560	3.74	3,093	38	12	0	3577.1	3,404	1,485	1,623	382	1,099	123	0	44	14,989	74	7.78	2.76	2.81	0.96	20.6	7.3	1.26	.294	4.08	87	3.77	87	8.56	223.7
4	Mark Buehrle M. Buehrle	160	214	.428	518	.572	493	3.81	1,870	33	10	0	3283.1	3,472	1,391	1,542	361	734	79	6	49	13,705	27	5.13	2.01	2.55	0.99	13.6	5.4	1.28	.292	4.23	87	4.11	93	9.52	111.9
5	Javier Vazquez J. Vazquez	160	165	.492	450	.508	443	4.22	2,536	28	8	0	2840.0	2,784	1,331	1,431	373	763	88	5	58	11,935	76	8.04	2.42	3.32	1.18	21.2	6.4	1.25	.295	4.53	96	3.90	88	8.82	164.4
6	A.J. Burnett	157	164	.489	435	.511	430	3.99	2,513	24	10	0	2731.1	2,519	1,210	1,328	263	1,100	143	1	35	11,665	161	8.28	3.62	2.28	0.87	21.5	9.4	1.32	.295	4.38	97	3.86	92	8.30	97.3
7	Zack Greinke Z. Greinke	156	225	.409	586	.591	541	3.49	2,979	17	5	1	3389.1	3,207	1,315	1,410	367	762	79	8	25	13,877	101	7.91	2.02	3.91	0.97	21.5	5.5	1.17	.293	3.74	83	3.51	85	8.52	235
8	Derek Lowe D. Lowe	151	174	.465	661	.535	368	3.97	1,670	10	4	86	2602.1	2,685	1,148	1,284	206	771	74	167	64	11,060	53	5.78	2.67	2.17	0.71	15.1	7.0	1.33	.297	4.44	92	3.80	89	9.29	141.3
9	Justin Verlander J. Verlander	149	262	.363	533	.637	533	3.31	3,448	26	9	0	3452.2	2,926	1,270	1,374	360	965	115	0	27	14,102	97	8.99	2.52	3.57	0.94	24.5	6.8	1.13	.278	3.58	78	3.42	81	7.63	307.5
10	Kevin Millwood K. Millwood	149	164	.476	439	.524	435	4.11	2,041	22	6	0	2669.0	2,715	1,220	1,331	295	822	72	1	45	11,389	66	6.88	2.77	2.48	0.99	17.9	7.2	1.33	.297	4.49	94	4.00	91	9.16	117.3
11	John Lackey J. Lackey	147	188	.439	448	.561	446	3.92	2,294	18	8	0	2840.1	2,862	1,237	1,347	319	815	133	0	32	12,030	125	7.27	2.58	2.81	1.01	19.1	6.8	1.29	.300	4.27	92	3.94	94	9.07	79.6
12	Aaron Harang A. Harang	143	128	.528	387	.472	381	4.26	1,842	15	8	0	2322.0	2,445	1,099	1,177	298	712	63	2	54	9,975	76	7.14	2.76	2.59	1.16	18.5	7.1	1.36	.304	4.56	103	4.17	100	9.48	12.3
13	Kyle Lohse K. Lohse	143	147	.493	457	.507	418	4.40	1,615	12	9	2	2531.2	2,711	1,239	1,327	316	694	87	15	34	10,839	57	5.74	2.47	2.33	1.12	14.9	6.4	1.34	.295	4.72	105	4.35	105	9.64	-58.3
14	Barry Zito B. Zito	143	165	.464	433	.536	421	4.04	1,885	12	5	0	2576.2	2,381	1,157	1,254	282	1,064	97	9	52	11,001	50	6.58	3.72	1.77	0.98	17.1	9.7	1.34	.274	4.38	97	4.38	104	8.32	-43.1
15	Jeff Suppan J. Suppan	140	131	.517	409	.483	388	4.62	1,291	16	5	0	2385.0	2,645	1,223	1,342	318	817	89	12	56	10,429	81	4.87	3.08	1.58	1.20	12.4	7.8	1.45	.294	5.06	103	4.87	110	9.98	-111.1
16	James Shields J. Shields	139	145	.489	407	.511	405	4.01	2,234	23	9	0	2616.0	2,581	1,167	1,267	361	746	97	1	22	10,993	107	7.69	2.57	2.99	1.24	20.3	6.8	1.27	.294	4.36	98	4.16	101	8.88	-13.5
17	Bronson Arroyo B. Arroyo	137	148	.481	419	.519	383	4.28	1,571	16	6	1	2435.2	2,507	1,158	1,260	347	661	105	6	60	10,338	42	5.80	2.44	2.38	1.28	15.2	6.4	1.30	.282	4.66	100	4.59	108	9.26	-82
18	Felix Hernandez F. Hernandez	136	169	.446	419	.554	418	3.42	2,524	25	11	0	2729.2	2,487	1,037	1,157	264	805	105	0	16	11,284	156	8.32	2.65	3.14	0.87	22.4	7.1	1.21	.293	3.81	84	3.52	85	8.20	181.5
19	Edwin Jackson E. Jackson	133	107	.554	412	.446	318	4.78	1,508	5	3	1	1960.0	2,094	1,040	1,135	249	779	39	30	39	8,569	108	6.92	3.58	1.94	1.14	17.6	9.1	1.47	.308	5.21	116	4.47	108	9.62	-74.1
20	Tim Hudson T. Hudson	133	222	.375	482	.625	479	3.49	2,080	26	13	0	3126.2	2,957	1,213	1,319	248	917	124	0	84	13,005	84	5.99	2.64	2.27	0.71	16.0	7.1	1.24	.281	3.80	83	3.78	90	8.51	152.3
21	Ryan Dempster R. Dempster	133	132	.502	579	.498	351	4.35	2,075	11	3	87	2387.0	2,347	1,154	1,250	267	1,071	91	186	47	10,412	80	7.82	4.04	1.94	1.01	19.9	10.3	1.43	.301	4.71	103	4.25	100	8.85	-1.1
22	Patrick Corbin P. Corbin	132	105	.557	346	.443	328	4.51	1,744	6	2	2	1911.1	2,042	957	1,031	266	585	48	9	23	8,230	63	8.21	2.75	2.98	1.25	21.2	7.1	1.37	.318	4.85	107	4.12	99	9.62	8.6
23	Tim Wakefield T. Wakefield	132	144	.478	496	.522	342	4.50	1,636	10	0	22	2397.2	2,337	1,200	1,346	317	850	139	75	25	10,338	104	6.14	3.19	1.92	1.19	15.8	8.2	1.33	.273	5.05	98	4.67	108	8.77	-96.8
24	Dan Haren D. Haren	131	153	.461	391	.539	380	3.75	2,013	16	6	1	2419.2	2,357	1,009	1,105	305	500	67	4	39	10,022	98	7.49	1.86	4.03	1.13	20.1	5.0	1.18	.288	4.11	92	3.77	92	8.77	92.8
25	Charlie Morton C. Morton	129	138	.483	390	.517	387	4.08	2,073	3	2	0	2152.1	2,028	976	1,074	209	808	187	0	25	9,239	69	8.67	3.38	2.57	0.87	22.4	8.7	1.32	.305	4.49	102	3.86	96	8.48	42.7