The Arizona Diamondbacks had the lowest run differential by a team in 2004, with a differential of -284 runs.

	TEAM	DIFF	SEASON	G	W%	W	L	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG	OPS
1	Diamondbacks	-284	2004	162	.315	51	111	5,544	615	1,401	295	38	135	582	441	35	1,022	53	32	6,113	2,177	468	56	37	38	137	.253	.310	.393	.703
2	Royals	-185	2004	162	.358	58	104	5,538	720	1,432	261	29	150	675	461	76	1,057	67	48	6,153	2,201	440	40	38	28	130	.259	.322	.397	.720
3	Reds	-157	2004	162	.469	76	86	5,518	750	1,380	287	28	194	713	599	81	1,335	77	25	6,278	2,305	509	55	25	38	125	.250	.331	.418	.749
4	Expos	-134	2004	162	.414	67	95	5,474	635	1,361	276	27	151	605	496	35	925	109	38	6,138	2,144	454	100	33	51	115	.249	.313	.392	.705
5	Devil Rays	-128	2004	161	.435	70	91	5,483	714	1,416	278	46	145	685	469	55	944	132	42	6,098	2,221	469	35	56	33	97	.258	.320	.405	.725
6	Mariners	-125	2004	162	.389	63	99	5,722	698	1,544	276	20	136	658	492	54	1,058	110	42	6,362	2,268	432	46	48	49	131	.270	.331	.396	.727
7	Brewers	-123	2004	161	.416	67	94	5,483	634	1,358	295	32	135	601	540	68	1,312	138	40	6,187	2,122	462	56	40	49	120	.248	.321	.387	.708
8	Blue Jays	-104	2004	161	.416	67	94	5,531	719	1,438	290	34	145	680	513	71	1,083	58	31	6,177	2,231	469	20	42	25	139	.260	.328	.403	.732
9	Rockies	-90	2004	162	.420	68	94	5,577	833	1,531	331	34	202	795	568	54	1,181	44	33	6,333	2,536	567	97	37	51	132	.275	.345	.455	.800
10	Pirates	-64	2004	161	.447	72	89	5,483	680	1,428	267	39	142	648	415	95	1,066	63	40	6,114	2,199	448	79	42	33	117	.260	.321	.401	.722
11	Mets	-47	2004	162	.438	71	91	5,532	684	1,376	289	20	185	658	512	61	1,159	107	23	6,208	2,260	494	69	34	54	129	.249	.317	.409	.726
12	Tigers	-17	2004	162	.444	72	90	5,623	827	1,531	284	54	201	800	518	50	1,144	86	50	6,284	2,526	539	50	43	32	110	.272	.337	.449	.786
13	Indians	1	2004	162	.494	80	82	5,676	858	1,565	345	29	184	820	606	78	1,009	94	55	6,449	2,520	558	47	42	41	143	.276	.351	.444	.795
14	Orioles	12	2004	162	.481	78	84	5,736	842	1,614	319	18	169	803	528	57	949	101	41	6,429	2,476	506	46	62	34	126	.281	.345	.432	.776
15	Marlins	18	2004	162	.512	83	79	5,486	718	1,447	275	32	148	677	499	58	968	96	43	6,160	2,230	455	77	40	37	142	.264	.329	.406	.736
16	White Sox	34	2004	162	.512	83	79	5,534	865	1,481	284	19	242	823	499	63	1,030	78	51	6,196	2,529	545	58	42	25	119	.268	.333	.457	.790
17	Athletics	51	2004	162	.562	91	71	5,728	793	1,545	336	15	189	752	608	55	1,061	47	22	6,459	2,478	540	25	43	40	142	.270	.343	.433	.776
18	Phillies	59	2004	162	.531	86	76	5,643	840	1,505	303	23	215	802	645	58	1,133	100	27	6,456	2,499	541	64	46	60	123	.267	.345	.443	.788
19	Padres	63	2004	162	.537	87	75	5,573	768	1,521	304	32	139	722	566	56	910	52	25	6,313	2,306	475	52	66	45	128	.273	.342	.414	.756
20	Twins	65	2004	162	.568	92	70	5,623	780	1,494	310	24	191	735	513	64	982	116	46	6,286	2,425	525	46	40	42	130	.266	.332	.431	.763
21	Rangers	66	2004	162	.549	89	73	5,615	860	1,492	323	34	227	825	500	61	1,099	69	36	6,256	2,564	584	23	57	41	91	.266	.329	.457	.786
22	Dodgers	77	2004	162	.574	93	69	5,542	761	1,450	226	30	203	731	536	62	1,092	102	41	6,244	2,345	459	69	35	45	121	.262	.332	.423	.755
23	Giants	80	2004	162	.562	91	71	5,546	850	1,500	314	33	183	805	705	72	874	43	23	6,466	2,429	530	92	51	153	142	.270	.357	.438	.795
24	Yankees	89	2004	162	.623	101	61	5,527	897	1,483	281	20	242	863	670	80	982	84	33	6,364	2,530	543	37	50	40	157	.268	.353	.458	.811
25	Angels	102	2004	162	.568	92	70	5,675	836	1,603	272	37	162	783	450	73	942	143	46	6,295	2,435	471	56	41	43	123	.282	.341	.429	.770