Between the 2006 and 2010 seasons, the Pittsburgh Pirates lost the most games by a team, with 488 losses.

Interpreted as:

most regular-season losses by a team from 2006 to 2010

	TEAM	L	W	L%	G	W%	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Pirates	488	321	.603	809	.397	27,558	3,373	7,046	1,487	130	693	3,237	2,358	298	5,723	370	140	30,740	10,872	2,310	306	220	192	637	.256	.319	.395	.713
2	Nationals	478	331	.591	809	.409	27,417	3,425	6,999	1,421	148	709	3,268	2,772	305	5,807	456	209	31,047	10,843	2,278	338	215	200	672	.255	.328	.395	.724
3	Orioles	472	337	.583	809	.417	27,972	3,660	7,519	1,487	120	771	3,480	2,448	255	4,876	498	182	31,051	11,559	2,378	149	227	160	680	.269	.331	.413	.744
4	Royals	472	338	.583	810	.417	27,867	3,516	7,435	1,493	193	611	3,325	2,222	280	5,110	425	195	30,793	11,147	2,297	208	216	142	712	.267	.325	.400	.725
5	Mariners	437	373	.540	810	.460	27,949	3,374	7,371	1,342	119	710	3,186	2,090	251	5,002	508	171	30,699	11,081	2,171	205	204	197	642	.264	.318	.396	.715
6	Diamondbacks	427	383	.527	810	.473	27,490	3,638	6,985	1,543	204	843	3,490	2,783	249	6,190	431	158	31,037	11,465	2,590	279	236	226	568	.254	.326	.417	.743
7	Indians	421	389	.520	810	.480	27,821	3,905	7,365	1,599	124	834	3,726	2,833	382	6,014	379	157	31,450	11,714	2,557	180	234	196	622	.265	.338	.421	.759
8	Astros	418	391	.517	809	.483	27,465	3,424	7,059	1,374	136	758	3,285	2,444	256	5,185	471	201	30,741	10,979	2,268	375	201	200	663	.257	.321	.400	.721
9	Reds	415	395	.512	810	.488	27,628	3,699	7,130	1,426	114	954	3,540	2,763	296	5,777	495	194	31,280	11,646	2,494	377	216	224	579	.258	.330	.422	.751
10	Giants	410	399	.507	809	.493	27,534	3,423	7,099	1,434	199	672	3,230	2,357	240	5,099	418	164	30,691	10,947	2,305	347	213	289	690	.258	.320	.398	.717
11	Athletics	409	400	.506	809	.494	27,560	3,580	7,037	1,414	112	715	3,398	2,942	244	5,428	490	147	31,145	10,820	2,241	147	252	112	697	.255	.330	.393	.722
12	Marlins	409	400	.506	809	.494	27,731	3,809	7,251	1,541	170	902	3,616	2,643	343	6,553	458	181	31,247	11,838	2,613	318	212	239	531	.261	.331	.427	.758
13	Padres	406	405	.501	811	.499	27,615	3,412	6,916	1,385	151	759	3,252	2,763	249	5,957	420	151	31,181	10,880	2,295	335	219	236	606	.250	.322	.394	.716
14	Rays	406	404	.501	810	.499	27,509	3,850	7,115	1,434	179	916	3,669	2,926	274	6,175	773	258	31,114	11,655	2,529	156	249	153	527	.259	.333	.424	.757
15	Brewers	405	405	.500	810	.500	27,638	3,816	7,171	1,509	162	973	3,658	2,709	379	6,020	424	170	31,216	11,923	2,644	265	225	231	585	.259	.331	.431	.763
16	Cubs	402	406	.498	808	.502	27,816	3,715	7,390	1,531	151	811	3,535	2,602	242	5,589	405	181	31,181	11,656	2,493	322	199	196	654	.266	.332	.419	.751
17	Rangers	399	411	.493	810	.507	28,103	4,123	7,642	1,595	146	942	3,922	2,586	241	5,731	494	158	31,386	12,355	2,683	205	251	165	620	.272	.336	.440	.775
18	Braves	398	412	.491	810	.509	27,878	3,885	7,456	1,568	131	816	3,719	2,914	246	5,545	295	147	31,611	11,734	2,515	366	207	251	689	.267	.340	.421	.761
19	Rockies	396	415	.488	811	.512	27,738	3,994	7,417	1,518	222	851	3,799	2,998	269	6,020	531	214	31,663	11,932	2,591	424	234	244	592	.267	.342	.430	.772
20	Blue Jays	394	416	.486	810	.514	27,826	3,829	7,358	1,653	117	956	3,676	2,587	269	5,080	333	125	31,058	12,113	2,726	137	239	145	687	.264	.330	.435	.766
21	White Sox	393	418	.485	811	.515	27,598	3,848	7,262	1,345	94	1,022	3,696	2,575	314	5,165	511	250	30,900	11,861	2,461	197	216	147	700	.263	.331	.430	.760
22	Tigers	387	424	.477	811	.523	28,223	4,024	7,687	1,492	198	915	3,857	2,562	247	5,524	367	164	31,437	12,320	2,605	200	205	175	641	.272	.336	.437	.773
23	Mets	387	423	.478	810	.522	27,687	3,764	7,336	1,452	195	772	3,568	2,743	237	5,099	736	205	31,322	11,494	2,419	389	266	300	602	.265	.333	.415	.749
24	Cardinals	385	424	.476	809	.524	27,694	3,751	7,474	1,433	113	809	3,562	2,683	268	4,884	342	169	31,210	11,560	2,355	344	221	331	684	.270	.338	.417	.755
25	Dodgers	381	429	.470	810	.530	27,766	3,702	7,430	1,402	190	684	3,512	2,795	244	5,107	599	240	31,391	11,264	2,276	351	235	297	673	.268	.337	.406	.743