2015 MLB Relative Power Index (RPI),as of the games of June 20,2015

MLB RPI Rankings
RK	TEAM	RPI	W	L	PCT	SOS	PWR	RS	RA	EXPW-L	EXPWP
1	St. Louis Cardinals	.540	45	23	.662	.499	1	277	193	46-22	.673
2	Kansas City Royals	.533	39	26	.600	.511	3	289	228	40-25	.616
3	New York Yankees	.525	38	30	.559	.514	8	322	288	38-30	.556
4	Tampa Bay Rays	.520	40	30	.571	.503	10	264	244	38-32	.539
5	Chicago Cubs	.517	36	30	.545	.507	9	276	262	35-31	.526
6	Minnesota Twins	.514	37	31	.544	.504	11	280	275	35-33	.509
7	Houston Astros	.514	40	30	.571	.494	7	308	273	39-31	.560
8	Toronto Blue Jays	.513	37	33	.529	.508	5	384	302	43-27	.618
9	Los Angeles Dodgers	.511	38	31	.551	.498	2	292	245	40-29	.587
10	Texas Rangers	.510	37	32	.536	.501	12	305	289	36-33	.527
11	Detroit Tigers	.509	34	34	.500	.512	15	281	294	32-36	.477
12	Pittsburgh Pirates	.507	39	29	.574	.485	4	271	219	41-27	.605
13	Baltimore Orioles	.507	35	33	.515	.505	16	304	267	38-30	.565
14	Los Angeles Angels	.506	35	34	.507	.506	17	277	273	35-34	.507
15	Cleveland Indians	.502	31	36	.463	.515	19	271	297	30-37	.454
16	Seattle Mariners	.500	32	37	.464	.513	21	236	280	29-40	.415
17	San Francisco Giants	.499	38	32	.543	.485	6	287	268	37-33	.534
18	San Diego Padres	.497	34	37	.479	.503	18	299	321	33-38	.465
19	Arizona Diamondbacks	.496	33	35	.485	.500	22	300	304	34-34	.493
20	New York Mets	.494	36	34	.514	.488	13	260	275	33-37	.472
21	Washington Nationals	.493	36	33	.522	.484	14	302	291	36-33	.519
22	Chicago White Sox	.490	29	38	.433	.509	23	229	298	25-42	.371
23	Oakland Athletics	.487	30	41	.423	.509	26	316	282	40-31	.557
24	Boston Red Sox	.484	30	40	.429	.503	28	276	332	29-41	.409
25	Cincinnati Reds	.484	31	36	.463	.491	24	270	286	32-35	.471
26	Atlanta Braves	.482	34	35	.493	.478	20	293	307	33-36	.477
27	Milwaukee Brewers	.476	25	45	.357	.515	29	255	336	26-44	.365
28	Miami Marlins	.474	30	40	.429	.490	25	269	286	33-37	.469
29	Colorado Rockies	.470	29	39	.426	.485	27	295	344	29-39	.424
30	Philadelphia Phillies	.448	23	47	.329	.487	30	211	340	19-51	.278

Glossary

• W: Wins
• L: Losses
• PCT: Winning percentage
• RPI: Relative Power Index+
• SOS: Strength of schedule

• PWR: ESPN Power Ranking
• RS: Runs scored
• RA: Runs allowed
• EXW-L: Expected W-L*
• EXWP: Expected winning percentage*

+The basic formula is 25% team winning percentage, 50% opponents' average winning percentage, and 25% opponents' opponents' average winning percentage.
*ExW-L and ExWP are derived from Bill James' Pythagorean theorem of baseball: Runs scored [squared] / (Runs scored [squared] + runs allowed [squared]). This formula was designed to relate a team's runs scored and runs allowed to its won-lost record.