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BtB Power Rankings: Week 13 - In the Aftermath of Interleague

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Allrank-063010_medium

"On Paper" Playoff Leaders

American League: E=Yankees, C=Twins, W=Rangers, WC=Rays
National League: E=Braves, C=Cardinals, W=Padres, WC=Marlins*

This Week's Breakdown

I made several changes under the hood that affect the power rankings this week.

1. The National League fared better against the AL this year than they have in years, and improved for the second consecutive year.  Consequently, I've decided to decrease the league adjustment to reflect the interleague record over the past two years.  So, instead of giving a 40 run/season boost to AL teams' run differentials (and a similar penalty to NL teams), I'm now only applying a 28 run/season adjustment.  The AL still is getting a considerable boost, but it's 30% less than it was a week ago.  We can re-evaluate as time goes on whether this is appropriate.

The consequence of this change was roughly a boost of ~0.008 TPI to NL teams, and a drop of ~0.008 TPI to AL teams.

2.  Thanks to a suggestion by Nick Steiner (vivaelpujols), I've modified the way I'm accounting for fielding.  Previously this year, I was just taking an average of UZR and DRS as reported at FanGraphs.  I was never entirely comfortable doing this, however, because both are based on the same dataset, and we've shown many times that there can be significant differences between datasets that can massively affect how we rate players.  Last year I had used THT's team fielding stat as a check against UZR, but they are no longer publishing it.  Nick suggested that I instead use the difference between xFIPruns (which I use to estimate pitcher runs allowed) and Base Runs (which I've opted to park adjust) as an additional measure of fielding (let's call it BsRFld).  There are many ways to drive differences between xFIPruns and Base Runs, but a big one is fielding ("luck" and unreconciled park effects are the others).  

Here's a correlation matrix showing how the three fielding measures relate to one another:

UZR DRS BsRFld
UZR 1.00 0.70 0.44
DRS 0.70 1.00 0.61
BsRFld 0.44 0.61 1.00

DRS and UZR correlate the best to one another, which is no surprise given that they are similar in construction and use the same BIS input data.  But I was pleased to see how comparably BsRFld correlated to DRS, even if the relationship to UZR is a bit weaker.  

So, I'm comfortable using this.  I've decided to now calculate my overall fielding stat as:

( 2*( (UZR+DRS)/2 + Catcher) + BsRFld)/3

As you an see, it's 2/3 "measured fielding" (DRS & UZR) and 1/3 BsRFld (or, if you like, 1/3 UZR, 1/3 DRS, and 1/3 BsRFld). "Catcher" is my home brew catcher stat, very much like what Matt posted the other day.  

One of the things that I like about incorporating this is that it helps soften some of the rare, large disparities between estimated runs and actual runs allowed in the power rankings.  The Diamondbacks are one of the teams most affected by this: last week, we estimated that they've allowed 74 more runs than expected based on xFIP and UZR/DRS.  Part of that could be (and probably is) some bad luck, but some of it could also be bad fielding.  We estimated their overall fielding at +4 runs (including catcher), but perhaps those estimates are off and they are instead a below-average fielding team (their park-adjusted defensive efficiency is 4th-worst in baseball).  This week, using our new approach to fielding, the power rankings have their fielding at -12 runs, and now they've "only" allowed 35 more runs than expected.  That's a number I can stomach a lot more than the 74 run total.

3. In looking at and comparing Matt's catcher data to my catcher data, I discovered an error in my spreadsheet.  I was vlookuping the wrong column from the catcher data page, and the result is that all of the catcher data that was being reported and used in the power rankings were wrong (or, at best, incomplete).  I don't know how long this has been going on (April?), but it's now corrected.  Sorry, I'm a dork.  At least, most of the time, it didn't make a big difference.

 

From all of that, the Rockies seem to be the team that benefited the most.  They surged 11 spots in the rankings and gained 38 points in TPI.  The Giants got a similar boost from the rule changes, but played so badly this past week that it doesn't show up in the rankings.  The team with the biggest dropoff from the methods changes were the Diamondbacks, who fell 5 spots and 44 points this week.

Hopefully you agree that the changes are improvements!

 

Under The Hood

Converting Runs to Wins

Team G RS eRS RA eRA W% pW% cW% xtW LgAdj TPI
ARI 79 342 343 421 386 0.392 0.401 0.444 68 -7 0.427
ATL 79 378 377 317 317 0.582 0.581 0.581 94 -7 0.563
BAL 77 273 299 410 405 0.312 0.318 0.363 55 7 0.379
BOS 79 422 435 357 358 0.595 0.580 0.593 96 7 0.609
CHW 77 325 313 331 326 0.519 0.492 0.481 81 7 0.500
CHC 78 300 311 328 317 0.436 0.460 0.491 75 -7 0.472
CIN 79 371 389 345 370 0.557 0.534 0.523 87 -7 0.506
CLE 77 326 322 400 380 0.390 0.403 0.422 66 7 0.439
COL 78 333 336 304 317 0.526 0.542 0.526 85 -7 0.507
DET 77 344 368 348 340 0.532 0.495 0.537 87 7 0.554
FLA 78 375 371 348 344 0.474 0.534 0.535 82 -7 0.517
HOU 79 282 248 406 370 0.392 0.336 0.322 58 -7 0.304
KCR 79 345 351 375 390 0.430 0.461 0.451 71 7 0.469
LAD 78 378 375 361 360 0.551 0.523 0.519 87 -7 0.502
LAA 80 386 350 389 393 0.550 0.496 0.445 80 7 0.463
MIL 78 383 402 410 401 0.449 0.467 0.500 77 -7 0.484
MIN 78 366 382 314 320 0.551 0.571 0.582 92 7 0.600
NYY 77 417 419 326 328 0.610 0.616 0.615 99 7 0.631
NYM 78 368 353 318 350 0.564 0.568 0.504 86 -7 0.487
OAK 79 329 335 341 345 0.481 0.483 0.486 78 7 0.505
PHI 76 354 334 312 327 0.539 0.560 0.509 85 -7 0.491
PIT 78 253 265 434 406 0.346 0.266 0.310 53 -7 0.294
SDP 78 362 333 287 291 0.590 0.605 0.561 93 -7 0.542
SEA 77 274 276 332 337 0.429 0.415 0.410 68 7 0.429
SFG 77 318 328 283 319 0.519 0.552 0.513 84 -7 0.494
STL 78 353 366 294 312 0.551 0.583 0.572 91 -7 0.554
TBR 77 394 381 299 309 0.584 0.627 0.597 96 7 0.615
TEX 77 404 398 324 341 0.610 0.604 0.574 96 7 0.590
TOR 79 354 340 347 330 0.506 0.509 0.514 83 7 0.533
WSN 79 318 324 359 361 0.430 0.443 0.450 71 -7 0.432

G=Games
RS = Actual Runs Scored, after a park adjustment
eRS = Estimated Runs Scored, after park adjustment (see "Offense" table below)
RA = Actual Runs Allowed, after a park adjustment
eRA = Estimated Runs Allowed, after park adjustments (see "Defense" table below)
W% = Actual Winning Percentage
pW% = PythagenPat Winning Percentage, based on actual runs scored and run allowed totals
cW% = Component Winning Percentage, using estimated runs scored and estimated runs allowed totals.  If you don't like the league adjustment, click in the header and sort by this column to get an "unsullied" ranking.
LgAdj = League adjustment, based on differences in league quality (justification here and here, and modified most recently here).  The number shown is the number of runs credited to both the offense and defense of AL teams, as well as the number penalized to both the offenses and defenses of NL teams.  By season's end, each team's run differential will be altered by 28 runs.
TPI = Team Performance Index, a hypothetical winning % based on component estimates of runs scored and runs allowed after the league adjustment.

 

Team Offenses and Defenses

Team RS eRS wOBA OBP SLG wRC EqBRR Clutch RA eRA ERA FIP xFIP xFIPrns Field BABIP
ARI 342 343 0.324 0.328 0.424 351 -8 -14 421 386 5.33 4.92 4.64 374 -12 0.317
ATL 378 377 0.333 0.347 0.392 374 4 4 317 317 3.76 3.86 4.08 326 9 0.295
BAL 273 299 0.311 0.318 0.378 301 -2 -5 410 405 5.02 4.83 4.84 378 -27 0.313
BOS 422 435 0.353 0.353 0.468 438 -3 4 357 358 4.33 4.18 4.52 373 15 0.298
CHW 325 313 0.318 0.322 0.402 315 -2 4 331 326 4.26 3.83 4.10 323 -3 0.312
CHC 300 311 0.314 0.321 0.398 315 -4 -44 328 317 3.89 3.94 4.11 325 8 0.303
CIN 371 389 0.338 0.340 0.444 386 4 4 345 370 4.42 4.37 4.56 373 3 0.307
CLE 326 322 0.319 0.323 0.381 323 -2 -7 400 380 4.72 4.54 4.75 371 -9 0.309
COL 333 336 0.317 0.332 0.414 329 7 -20 304 317 3.92 3.81 4.19 335 18 0.301
DET 344 368 0.335 0.341 0.418 368 0 15 348 340 4.32 4.13 4.61 359 19 0.300
FLA 375 371 0.331 0.332 0.409 365 6 -26 348 344 4.08 3.85 4.28 341 -3 0.309
HOU 282 248 0.290 0.294 0.343 246 2 44 406 370 4.64 4.03 4.28 342 -28 0.333
KCR 345 351 0.325 0.337 0.408 350 1 -15 375 390 4.67 4.50 4.64 374 -15 0.304
LAD 378 375 0.332 0.338 0.405 368 7 -6 361 360 4.07 3.96 4.17 336 -25 0.304
LAA 386 350 0.326 0.324 0.410 353 -2 23 389 393 4.46 4.28 4.43 363 -30 0.314
MIL 383 402 0.342 0.336 0.436 402 0 -22 410 401 4.88 4.30 4.42 354 -47 0.332
MIN 366 382 0.339 0.347 0.419 384 -2 -13 314 320 3.90 3.91 4.17 334 15 0.304
NYY 417 419 0.351 0.356 0.435 420 -1 8 326 328 4.01 4.24 4.25 333 5 0.285
NYM 368 353 0.328 0.325 0.404 349 4 -6 318 350 3.84 4.15 4.43 358 8 0.308
OAK 329 335 0.321 0.324 0.383 337 -2 -3 341 345 3.98 4.33 4.32 348 3 0.289
PHI 354 334 0.326 0.330 0.417 341 -7 23 312 327 4.01 4.31 4.25 329 2 0.294
PIT 253 265 0.300 0.304 0.356 270 -5 7 434 406 5.15 4.74 4.73 372 -35 0.319
SDP 362 333 0.320 0.318 0.367 332 1 -1 287 291 3.13 3.63 3.80 310 19 0.286
SEA 274 276 0.304 0.310 0.350 278 -2 11 332 337 3.83 4.10 4.49 355 18 0.288
SFG 318 328 0.321 0.326 0.400 327 1 -13 283 319 3.46 3.86 4.35 347 28 0.287
STL 353 366 0.332 0.334 0.410 367 -1 -13 294 312 3.24 3.86 4.05 326 15 0.292
TBR 394 381 0.335 0.338 0.403 375 6 -28 299 309 3.57 4.11 4.15 330 22 0.283
TEX 404 398 0.340 0.347 0.434 388 10 12 324 341 3.94 4.31 4.49 359 18 0.287
TOR 354 340 0.326 0.306 0.438 343 -3 5 347 330 4.17 3.94 4.14 334 3 0.300
WSN 318 324 0.319 0.325 0.396 329 -5 -20 359 361 4.10 4.26 4.56 366 6 0.308

RS = Actual Runs Scored
eRS = Estimated Runs Scored: wRC + EqBRR
wOBA The Book's statistic, but park adjusted, and using data from both wRC and EqBRR
OBP = On Base Percentage (Times on Base / Plate Appearances)
SLG = Slugging Percentage (Total Bases / At Bats)
wRC = From FanGraphs, with baserunning removed, after park adjustments
EqBRR = Dan Fox's composite baserunning statistics from Baseball Prospectus, minus stolen bases since they are included in wRC.
Clutch = "Clutchiness" measure from fangraphs; difference between actual WPA and expected WPA based on component statistics.  We report this in runs.

RA = Actual Runs Allowed, after park adjustment
eRA = Estimated Runs Allowed: xFIPRns - Field
ERA = Straight-up Earned Run Average
FIP = Fielding-Independent Runs, based strictly on K-, BB-, and HR-rates.
xFIP = Experimental Fielding-Independent Runs from FanGraphs.  Like FIP, but with HR/Outfield Fly Ball rates regressed completely to league average.  xFIP is as predictive as any other DIPS-like stat.
xFIPrns = Pitching Runs Allowed, based on xFIP
Field = Described in this post.  It is essentially an average of team UZR, DRS (minus rSB since I calculate catcher fielding separately), and BsRFld.  BsRFld is just difference between xFIPRns and park-adjusted Base Runs, and is a less direct approach of measuring fielding.  The fielding number also includes a catcher fielding statistic, based on SB's, CS's, WP's, PB's, E's, and this year catcher interference.  The methods are essentially those described here.  But I'm using B-Ref data this year, and so there are slight tweaks to the methodology, generally in ways that should lead to greater accuracy.
BABIP = Batting Average on Balls In Play.  Fluctuates at the team level with fielding, although park effects and chance events can have effects as well.