MLB Power Rankings: Shifting Power in the American League

With methods described in this post, here are the latest MLB power rankings!

TPI = Team Performance Index (my ranking metric).  Based on wRC, DRA, DRS, and UZR.
W% = Team Winning Percentage (i.e. real life)
Py% = Pythagorean Winning Percentage (based on real RS and RA)

On-Paper Playoff Leaders

American League - East: Yankees, Central: Tigers, West: Astros, Wild cards: Royals and A's
National League - East: Nationals, Central: Cardinals, West: Dodgers, Wild cards: Giants and Pirates

This update sees new leaders in all three American League divisions.  Having just recently risen to the top in the last update, the Orioles have now (barely) fallen behind both the Yankees and Blue Jays in the AL East.  The Tigers surged past the Royals in the AL Central, while the upstart Astros jumped past the Athletics to take the AL West lead heading into the All Star Break.

This is a far more optimistic appraisal of the Tigers team than you'll likely see elsewhere, with Detroit sporting a .500 record and a sub-.500 Pythagorean record.  Nevertheless, the Tigers' offense is third in baseball in expected runs scored, and this is enough to overcome their fairly average run prevention.  This framework sees both their actual runs scored and actual runs allowed as worse than expected, based on the underlying numbers.  The Tigers were certainly expected to be better than a .500 ballclub, so I think there might be something to it.