BtB Power Rankings: Through Wednesday, September 16th, 2009

Welcome to our weekly ranking of all the MLB teams!  In this ranking, we use aggregate team hitting, baserunning, pitching, and fielding statistics--not team wins, losses, runs scored, or runs allowed--to evaluate the performance of teams to date.  You can think of the estimated winning percentage (eW%) below as how we'd expect things to fall out if we threw teams with these aggregate statistics into one big league and let them battle it out for thousands of games.  They don't replace your actual standings, but they give you something different to consider when thinking about team performances.

New this week: catcher defense!  All year, I've neglected to include any measure of catcher defense in these rankings.  This has now been addressed.  I'm using an approach similar to what Rally does in WAR and chuckb did here at BtB last month.  My specific methods were laid out in this piece from a few years back.


The table is sortable if you click in the header.  All data are park-adjusted when possible.  A legend is below the table, followed by commentary.

Beyond The Boxscore Power Rankings

Offense

wOBA (park-adjusted, includes BPro's baserunning data)
eRS (estimated runs scored) = wRC + EqBRR
wRC (wRC from FanGraphs, with baserunning removed, then park adjusted)
EqBRR (Equivalent Base Running Runs from Baseball Prospectus)

Defense

tERA (a home-brew version of Graham MacAree's statistic)
tRns (tERA converted to expected runs allowed)
Fld (Average of bUZR & THT, plus Catchers)
bUZR (from FanGraphs)
THT (their team batted balls statistic, converted to runs)
Catchers (catcher fielding based on SB's, CS, WP+PB, and E's)
eRA (estimated runs allowed) = tRns - Fld

The Rest
eW%lg = estimated winning percentage within the specific league (AL or NL).  Compare this to true winning %!
LgAdj = league adjustment (bonus to AL teams, penalty to NL teams, because the AL has superior level of play)
eW% = estimated winning percentage if all teams were in one league (after league adjustment)

Methods provided in more detail in the first post in this series

Team Leaders (asterisks indicate teams improving in specific ranking):

American League

Offense (wOBA): Yankees, Angels, Rays
Pitching (tERA): White Sox, Red Sox, Royals
Fielding (Fld): Mariners, Rangers, Rays

National League
Offense (wOBA): Marlins, Phillies, Dodgers
Pitching (tERA): Rockies, Dodgers*, Braves
Fielding (Fld): Reds*, Giants, Phillies

"On Paper" Playoff Leaders (asterisks indicate new leaders):

American League: E=Yankees, C=White Sox, W=Rangers, WC=Red Sox*
National League: E=Phillies, C=Cardinals, W=Dodgers*, WC=Rockies

This Week's Movers

I ran out of space for columns in the above table.  But based on our measure of catcher fielding, here are the best- and worst-caught teams in baseball:

Detroit: +12 runs
Cincinnati: +10 runs
St. Louis: +8 runs
New York Mets: +8 runs
Chicago Cubs: +8 runs
..........................................
Los Angeles Angels: -7 runs
Boston: -7 runs
Washington: -8 runs
Arizona: -13 runs
Kansas City: -16 runs

So the story just keeps getting worse for the Royals' fielding numbers...

If you look up and check out the teams most affected, it's a mixed bag in terms of how much this pushed teams up or down in the rankings this weak.  Detroit held constant, the catcher data bouying them up despite recent struggles.  Cincinnati got themselves out of the cellar, with poor Pittsburgh imploding.  The Cardinals and Mets both slipped a spot despite the boost to their fielding numbers.  On the other side of the coin, the Royals actually gained a spot thanks to a hot week that had them winning 4 of 5 from the aforementioned Tigers. 

Nevertheless, it's an important addition that alleviates a long-standing critique of these rankings.  The data we're using don't emcompass the entirety of catcher fielding, but they do cover the parts that are both repeatable and easily-measured.  Thanks to the Hardball Times for the data.

In other news...the Rays fell out of the on-paper playoff pitcher for the first time I can remember, replaced by the actual leaders: the Red Sox.  Similarly, the Dodgers bumped the Rockies back down to the wild card in the NL West.  The only races at this point that differ from reality are in the AL Central (White Sox over Tigers and Twins) and the AL West (Rangers over Angels).