2015 MLB Relative Power Index (RPI),as of the games of May 8,2015

MLB RPI Rankings
RK	TEAM	RPI	W	L	PCT	SOS	PWR	RS	RA	EXPW-L	EXPWP
1	St. Louis Cardinals	.559	22	7	.759	.493	1	134	84	21-8	.718
2	New York Yankees	.558	19	11	.633	.532	7	141	111	19-11	.617
3	Detroit Tigers	.552	19	11	.633	.525	4	135	125	16-14	.538
4	New York Mets	.532	18	11	.621	.502	6	110	89	18-11	.604
5	Kansas City Royals	.528	18	11	.621	.497	2	148	106	19-10	.661
6	Los Angeles Dodgers	.524	19	10	.655	.480	5	145	98	20-9	.686
7	Minnesota Twins	.519	17	13	.567	.503	21	142	123	17-13	.571
8	Chicago Cubs	.519	15	13	.536	.513	8	121	121	14-14	.500
9	San Diego Padres	.518	16	15	.516	.518	10	146	144	16-15	.507
10	Tampa Bay Rays	.513	16	14	.533	.506	9	113	107	16-14	.527
11	Washington Nationals	.505	15	15	.500	.507	15	128	124	15-15	.516
12	Toronto Blue Jays	.503	15	15	.500	.504	17	162	146	17-13	.552
13	Cincinnati Reds	.501	14	14	.500	.501	20	112	116	14-14	.482
14	San Francisco Giants	.499	15	15	.500	.499	18	96	116	12-18	.406
15	Houston Astros	.498	19	11	.633	.453	3	133	112	18-12	.585
16	Chicago White Sox	.497	10	15	.400	.530	27	83	120	8-17	.324
17	Baltimore Orioles	.497	12	15	.444	.515	14	130	125	14-13	.520
18	Arizona Diamondbacks	.494	13	15	.464	.504	25	134	115	16-12	.576
19	Miami Marlins	.489	14	16	.467	.497	12	128	118	16-14	.541
20	Pittsburgh Pirates	.489	13	16	.448	.503	11	106	98	16-13	.539
21	Atlanta Braves	.489	14	15	.483	.491	24	127	133	14-15	.477
22	Boston Red Sox	.487	13	16	.448	.499	13	128	151	12-17	.418
23	Cleveland Indians	.484	10	18	.357	.526	26	122	144	12-16	.418
24	Philadelphia Phillies	.473	11	19	.367	.508	29	85	141	8-22	.267
25	Los Angeles Angels	.470	14	16	.467	.471	16	110	114	14-16	.482
26	Colorado Rockies	.469	11	16	.407	.489	19	108	151	9-18	.338
27	Seattle Mariners	.468	12	17	.414	.486	22	106	132	11-18	.392
28	Milwaukee Brewers	.459	9	21	.300	.512	30	104	158	9-21	.302
29	Oakland Athletics	.457	12	19	.387	.480	23	148	145	16-15	.510
30	Texas Rangers	.445	12	17	.414	.456	28	116	134	12-17	.428

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.