TUTORIAL IT

And Even More Refinements in SFR

And Even More Refinements in SFR

As some readers will know Ive been writing the last couple weeks here and on Baseball Prospectus about a play by play fielding system termed Simple Fielding Runs or SFR.

After last weeks column I had a chance to tweak the system yet again, and made the following changes.

Took into consideration the additional context of whether first base was occupied for all infielders. It turns out that for first baseman on ground balls hit by lefties the percentage of runners who reach (hit or error) goes from 16% to 24% when first is occupied, and from 20% to 29% for right-handers. For second baseman in the same scenarios it goes from 27% to 29% and 30% to 34%, for shortstops, interestingly, the trend is the opposite as it goes from 34% to 30% and 32% to 31%, and for third baseman its pretty steady at 27% to 27% and 24% to 26%. Although a smaller percentage of fielded balls, the differences are significant for bunts when there is a runner on first since the vast majority of such attempts are sacrifice bunts instead of bunt hit attempts which have a higher success rate. The end result, Im hoping, is a higher correlation with UZR for first baseman. I have not, however, taken into consideration the ability of first baseman to catch throws from infielders.

Changed the partitioning rules for which balls are assigned to first and third baseman. In the past I was partitioning all balls in the shared areas of responsibility except for middle infielders all line drives that resulted in extra base hits. Now I also exclude bunts from the calculation as well and assign all extra base hits on ground balls to left field to the third baseman and all extra base hits on grounders to right to the first baseman on the assumption that theyre hit down the line. I also no longer partition any fly balls or line drives to the outfield since by doing so we didnt seem to be adding much information to what we already knew. Finally, in the last column on the subject I noted that I used a 50/50 split on ground balls up the middle. After the article was submitted, however, I realized that there is a simple way to partition balls between the short and second area of responsibility following the same principle outlined in the column. That change has been made.

While I havent re-run the correlations with UZR I did want to show a few results and so here are all infielders who were assigned 15 or more balls in 2007 in the National League Central. Youll notice that the range is smaller with Milwaukees infield not looking quite so terrible as in previous versions of the system.

Team Name POS Balls SFR
CHN Carlos Zambrano 1 33 0.6
CHN Jason Marquis 1 30 -0.4
CHN Rich Hill 1 26 -1.7
CHN Ted Lilly 1 30 -1.8
CHN Sean Marshall 1 17 -2.3
CHN Jason Kendall 2 17 -0.5
CHN Michael Barrett 2 23 -0.9
CHN Daryle Ward 3 21 -1.5
CHN Derrek Lee 3 294 -1.8
CHN Ryan Theriot 4 102 1.3
CHN Ronny Cedeno 4 18 0.9
CHN Mike Fontenot 4 200 0.1
CHN Mark DeRosa 4 295 -0.1
CHN Aramis Ramirez 5 406 7.1
CHN Mark DeRosa 5 103 4.9
CHN Cesar Izturis 6 189 2.3
CHN Ryan Theriot 6 405 2.1
CHN Ronny Cedeno 6 48 2.0
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CIN Bobby Livingston 1 17 1.4
CIN Aaron Harang 1 25 0.8
CIN Bronson Arroyo 1 32 -0.4
CIN Matt Belisle 1 18 -0.9
CIN Javier Valentin 2 21 0.0
CIN David Ross 2 49 -0.5
CIN Scott Hatteberg 3 167 1.2
CIN Jeff Conine 3 91 0.1
CIN Jorge Cantu 3 17 -0.9
CIN Joey Votto 3 32 -1.1
CIN Jeff Keppinger 4 16 0.3
CIN Brandon Phillips 4 662 -10.0
CIN Jeff Keppinger 5 34 1.8
CIN Ryan Freel 5 52 0.5
CIN Juan Castro 5 21 -1.5
CIN Edwin Encarnacion 5 402 -10.5
CIN Alex Gonzalez 6 420 2.0
CIN Juan Castro 6 44 -0.5
CIN Jeff Keppinger 6 184 -1.6
CIN Pedro Lopez 6 41 -1.7
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HOU Chris Sampson 1 25 1.9
HOU Roy Oswalt 1 38 1.2
HOU Wandy Rodriguez 1 22 1.0
HOU Woody Williams 1 40 0.2
HOU Dave Borkowski 1 21 0.0
HOU Brad Ausmus 2 35 0.1
HOU Eric Munson 2 18 -0.2
HOU Mark Loretta 3 51 2.9
HOU Mike Lamb 3 67 -1.1
HOU Lance Berkman 3 277 -3.5
HOU Chris Burke 4 150 2.5
HOU Mark Loretta 4 77 -0.3
HOU Craig Biggio 4 398 -9.7
HOU Ty Wigginton 5 143 1.7
HOU Mark Loretta 5 48 -0.5
HOU Mike Lamb 5 144 -3.5
HOU Morgan Ensberg 5 186 -9.0
HOU Adam Everett 6 281 9.4
HOU Eric Bruntlett 6 180 0.3
HOU Cody Ransom 6 35 -0.1
HOU Mark Loretta 6 248 -2.2
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MIL Jeff Suppan 1 35 2.1
MIL Chris Capuano 1 30 1.1
MIL Dave Bush 1 26 0.4
MIL Claudio Vargas 1 15 0.2
MIL Johnny Estrada 2 38 0.8
MIL Tony Graffanino 3 25 0.7
MIL Prince Fielder 3 325 -9.7
MIL Craig Counsell 4 84 3.0
MIL Tony Graffanino 4 92 0.5
MIL Rickie Weeks 4 439 -21.4
MIL Craig Counsell 5 112 3.9
MIL Tony Graffanino 5 74 2.2
MIL Ryan Braun 5 309 -24.7
MIL Craig Counsell 6 79 -0.1
MIL J.J. Hardy 6 619 -1.7
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PIT Matt Morris 1 18 1.6
PIT Ian Snell 1 20 1.6
PIT Paul Maholm 1 35 0.8
PIT Shawn Chacon 1 20 0.4
PIT Tom Gorzelanny 1 28 -0.4
PIT Zach Duke 1 23 -0.6
PIT Ronny Paulino 2 42 0.7
PIT Adam LaRoche 3 327 3.0
PIT Josh Phelps 3 25 1.2
PIT Matt Kata 4 18 -1.9
PIT Jose Castillo 4 56 -5.7
PIT Freddy Sanchez 4 526 -13.0
PIT Jose Castillo 5 130 2.6
PIT Matt Kata 5 23 0.1
PIT Jose Bautista 5 410 -4.8
PIT Cesar Izturis 6 107 -0.5
PIT Jack Wilson 6 665 -0.6
PIT Jose Castillo 6 32 -0.6
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SLN Adam Wainwright 1 29 1.8
SLN Braden Looper 1 21 0.4
SLN Joel Pineiro 1 15 0.2
SLN Kip Wells 1 23 -0.5
SLN Yadier Molina 2 34 0.9
SLN Gary Bennett 2 17 0.1
SLN Albert Pujols 3 396 10.6
SLN Brendan Ryan 4 64 1.3
SLN Miguel Cairo 4 19 0.6
SLN Aaron Miles 4 242 -0.8
SLN Adam Kennedy 4 333 -2.8
SLN Scott Rolen 5 351 13.7
SLN Scott Spiezio 5 68 2.4
SLN Russell Branyan 5 28 1.6
SLN Miguel Cairo 5 31 1.5
SLN Brendan Ryan 5 72 0.3
SLN Brendan Ryan 6 91 3.7
SLN Brian Barden 6 17 1.0
SLN David Eckstein 6 493 -7.2
SLN Aaron Miles 6 155 -8.6

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