2017 MLB Relative Power Index (RPI),as of the games of September 10,2017 from ESPN.GO.COM

MLB RPI Rankings
RK	TEAM	RPI	W	L	PCT	SOS	PWR	RS	RA	EXPW-L	EXPWP
1	Los Angeles Dodgers	.534	92	51	.643	.498	0	681	513	91-52	.638
2	Houston Astros	.526	86	57	.601	.501	0	788	644	86-57	.600
3	Cleveland Indians	.526	87	56	.608	.498	0	722	515	95-48	.663
4	Arizona Diamondbacks	.525	83	60	.580	.506	0	710	573	87-56	.606
5	Washington Nationals	.519	88	55	.615	.487	0	748	591	88-55	.616
6	Boston Red Sox	.517	81	62	.566	.501	0	681	588	82-61	.573
7	New York Yankees	.514	77	65	.542	.505	0	750	598	87-55	.611
8	Colorado Rockies	.514	78	65	.545	.503	0	733	684	76-67	.535
9	Minnesota Twins	.506	74	69	.517	.502	0	705	715	70-73	.493
10	Baltimore Orioles	.505	71	72	.497	.508	0	684	725	67-76	.471
11	Chicago Cubs	.505	77	66	.538	.494	0	707	636	79-64	.553
12	Los Angeles Angels	.505	73	70	.510	.503	0	635	631	72-71	.503
13	Milwaukee Brewers	.505	75	68	.524	.498	0	648	624	74-69	.519
14	St. Louis Cardinals	.504	75	68	.524	.497	0	678	604	80-63	.558
15	Texas Rangers	.502	71	71	.500	.502	0	736	699	75-67	.526
16	Kansas City Royals	.501	71	71	.500	.502	0	626	690	64-78	.451
17	Tampa Bay Rays	.501	71	73	.493	.503	0	620	632	71-73	.490
18	Seattle Mariners	.499	71	72	.497	.500	0	661	682	69-74	.484
19	Toronto Blue Jays	.493	66	77	.462	.504	0	612	702	62-81	.432
20	San Diego Padres	.491	65	79	.451	.504	0	556	700	56-88	.387
21	Oakland Athletics	.489	63	80	.441	.505	0	657	749	62-81	.435
22	Pittsburgh Pirates	.488	67	77	.465	.496	0	593	664	64-80	.444
23	Miami Marlins	.486	68	75	.476	.490	0	663	701	68-75	.472
24	Detroit Tigers	.485	60	82	.423	.506	0	665	765	61-81	.430
25	Cincinnati Reds	.484	62	82	.431	.502	0	686	780	63-81	.436
26	New York Mets	.482	63	80	.441	.495	0	663	741	64-79	.445
27	Atlanta Braves	.481	64	78	.451	.491	0	657	737	63-79	.443
28	Chicago White Sox	.478	56	86	.394	.505	0	612	728	59-83	.414
29	San Francisco Giants	.472	56	89	.386	.501	0	574	719	56-89	.389
30	Philadelphia Phillies	.467	54	89	.378	.497	0	595	716	58-85	.408

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.