Nolan Ryan has the most career losses when allowing 1+ run, with 292 games.

Interpreted as:

most one or more run game regular-season losses by a player

	NAME	L	R	W	L%	G	W%	GS	ERA	SO	CG	SHO	SV	IP	H	ER	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Nolan Ryan N. Ryan	292	1,255	0	1.000	292	.000	291	5.60	1,828	59	0	0	1775.1	1,690	1,104	174	1,125	65	1	49	8,055	135	9.27	5.70	1.62	0.88	22.7	14.0	1.59	.312	6.36	8.57
2	Walter Johnson W. Johnson	279	1,086	0	1.000	279	.000	249	2.60	1,114	187	0	0	2045.0	2,117		48	550	92	28			71	4.90	2.42	2.03	0.21		6.4	1.30	.303	4.78	9.32
3	Phil Niekro P. Niekro	274	1,172	0	1.000	274	.000	262	5.37	1,054	63	0	0	1698.0	1,976	1,013	222	637	38	7	54	7,601	92	5.59	3.38	1.65	1.18	13.9	8.4	1.54	.310	6.21	10.47
4	Gaylord Perry G. Perry	265	1,114	0	1.000	265	.000	252	5.26	1,116	76	0	0	1678.1	1,962	980	204	522	46	9	99	7,398	67	5.98	2.80	2.14	1.09	15.1	7.1	1.48	.319	5.97	10.52
5	Don Sutton D. Sutton	256	1,057	0	1.000	256	.000	253	5.70	1,025	27	0	0	1515.1	1,772	960	197	470	37	2	57	6,740	43	6.09	2.79	2.18	1.17	15.2	7.0	1.48	.314	6.28	10.52
6	Eppa Rixey E. Rixey	251	1,080	0	1.000	251	.000	239	4.72	496	76	0	0	1601.0	1,987	840	51	459	31	9		7,104	43	2.79	2.58	1.08	0.29	7.0	6.5	1.53	.319	6.07	11.17
7	Bert Blyleven B. Blyleven	250	1,073	0	1.000	250	.000	248	5.40	1,163	75	0	0	1630.2	1,890	979	214	479	72	2	41	7,156	47	6.42	2.64	2.43	1.18	16.3	6.7	1.45	.321	5.92	10.43
8	Robin Roberts R. Roberts	245	1,033	0	1.000	245	.000	240	5.26	767	66	0	0	1580.0	1,906	924	248	365	18	5	45	6,910	12	4.37	2.08	2.10	1.41	11.1	5.3	1.44	.301	5.88	10.86
9	Warren Spahn W. Spahn	245	971	0	1.000	245	.000	227	5.21	746	58	0	0	1505.0	1,751	872	185	501	17	15	34	6,663	30	4.46	3.00	1.49	1.11	11.2	7.5	1.50	.300	5.81	10.47
10	Steve Carlton S. Carlton	244	1,032	0	1.000	244	.000	240	5.28	1,168	38	0	0	1517.1	1,700	890	179	678	17	1	84	6,810	57	6.93	4.02	1.72	1.06	17.2	10.0	1.57	.319	6.12	10.08
11	Early Wynn E. Wynn	244	1,109	0	1.000	244	.000	232	5.94	680	65	0	0	1453.0	1,767	959	162	679	22	10	25	6,715	18	4.21	4.21	1.00	1.00	10.1	10.1	1.68	.310	6.87	10.94
12	Jim Kaat J. Kaat	237	887	0	1.000	237	.000	217	5.40	661	33	0	0	1247.2	1,520	749	159	372	51	10	44	5,604	41	4.77	2.68	1.78	1.15	11.8	6.6	1.52	.312	6.40	10.96
13	Frank Tanana F. Tanana	236	1,000	0	1.000	236	.000	236	5.65	882	44	0	0	1415.1	1,646	888	213	506	56	0	63	6,339	46	5.61	3.22	1.74	1.35	13.9	8.0	1.52	.306	6.36	10.47
14	Tommy John T. John	231	950	0	1.000	231	.000	228	5.72	600	33	0	0	1276.2	1,661	812	128	445	31	0	54	5,832	80	4.23	3.14	1.35	0.90	10.3	7.6	1.65	.331	6.70	11.71
15	Bob Friend B. Friend	230	931	0	1.000	230	.000	218	5.64	576	28	0	0	1287.0	1,652	807	141	372	16	7	61	5,789	26	4.03	2.60	1.55	0.99	9.9	6.4	1.57	.323	6.51	11.55
16	Ted Lyons T. Lyons	230	1,188	0	1.000	230	.000	210	5.55	430	119	0	0	1585.2	2,062	977	116	522	21	17		7,251	29	2.44	2.96	0.82	0.66	5.9	7.2	1.63	.316	6.74	11.70
17	Greg Maddux G. Maddux	227	983	0	1.000	227	.000	226	5.66	917	17	0	0	1372.2	1,699	864	159	369	55	1	99	6,128	22	6.01	2.42	2.49	1.04	15.0	6.0	1.51	.333	6.45	11.14
18	Fergie Jenkins F. Jenkins	226	925	0	1.000	226	.000	218	5.27	1,004	59	0	0	1430.2	1,591	838	221	414	35	5	65	6,242	25	6.32	2.60	2.43	1.39	16.1	6.6	1.40	.300	5.82	10.01
19	Red Ruffing R. Ruffing	225	1,127	0	1.000	225	.000	212	5.69	654	107	0	0	1521.1	1,827	962	134	620	27	12		6,909	16	3.87	3.67	1.05	0.79	9.5	9.0	1.61	.309	6.67	10.81
20	Bobo Newsom B. Newsom	222	1,058	0	1.000	222	.000	207	6.27	699	73	0	0	1328.0	1,677	925	90	690	27	8		6,269	18	4.74	4.68	1.01	0.61	11.2	11.0	1.78	.333	7.17	11.37
21	Sad Sam Jones S. Sam Jones	217	1,033	0	1.000	217	.000	200	5.92	404	72	0	0	1291.2	1,690	849	71	512	29	11		5,971	35	2.81	3.57	0.79	0.49	6.8	8.6	1.70	.327	7.20	11.78
22	Jack Quinn J. Quinn	217	930	0	1.000	217	.000	185	4.34	429	76	0	0	1293.1	1,644		54	342	39	23			24	2.99	2.38	1.25	0.38		6.3	1.54	.350	6.47	11.44
23	Charlie Hough C. Hough	216	856	0	1.000	216	.000	173	6.11	698	35	0	0	1112.1	1,218	755	173	577	59	28	20	5,083	64	5.65	4.67	1.21	1.40	13.7	11.4	1.61	.292	6.93	9.85
24	Red Faber R. Faber	213	872	0	1.000	213	.000	186	4.69	454	70	0	0	1309.2	1,588	682	50	409	47	23		5,849	17	3.12	2.81	1.11	0.34	7.8	7.0	1.52	.315	5.99	10.91
25	Paul Derringer P. Derringer	212	925	0	1.000	212	.000	189	5.42	507	65	0	0	1304.0	1,693	785	87	341	16	20		5,896	26	3.50	2.35	1.49	0.60	8.6	5.8	1.56	.325	6.38	11.68