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When Do 10 Runs Not Equal a Win? Baseball Databank Data Dump 2.2

Rpw1871_2010btb

I tried to start this baseball-databank data dump series for myself last season, but it didn't take. I'm hoping to have better luck this season with shorter, and, uh, "dumpier" posts. So, for your breathless perusal (drum roll please)... historical runs-per-win conversions!

As common sense would tell you (and as you might infer from a basic of baseball history combined with the plot above), the more offense-oriented the run environment, the more runs it take to lead to a "win." I won't get into all the details here, as it's done well elsewhere (for example, at the Saber Library). There are different runs-per-win estimators ranging from from simply league runs allowed per game times two to PythagenPat. For the graph above and the data below, I've used two estimators: Tom Tango's relatively simple (lgRA*1.5)+3, and Patriot's more sophisticated PythagenPat: (lgRPG^(1-z)) * 2, where z is between 0.27 and 0.29 (last season I used 0.287, but Patriot has since told me that 0.28 has been found to  "work" the best, historically). PythagenPat is considered to be the most accurate, but as you can see above, Tango's simple conversion tracks it extremely closely, with a bigger difference at in more "extreme" environments.

But is 10 runs still a win? Taking baseball as a whole, yes, as you'll see. Even if I separate the 2010 leagues, the NL (where runs are more scarce) runs-to-wins overall conversion is still closer to 10 than to 9. Let's take a look at "modern times" (1947 to the present). 

Rpw19472010

 

Both estimators see the last season a win was closer to nine runs than 10 was 1992. However, 2010 was closest since that season, at about 9.6 runs per win according to both estimators. It wouldn't take much of a drop to put it closer to nine than 10. In any case, to get a sense for how much of a difference between 9.6 and 10 runs per win makes, take a player who is 50 runs above average offensively. In a 10 rpw environment, that's worth ive wins. In a 9.6 rpw environment, that's worth 5.2 wins. I suppose it depends on how much accuracy you're after... Enough talk, here is the table (thrilling, isn't it?):

 

Runs per Win, 1871-2010

Season

RPG

TangoRPW

PatRPW

2010

4.4284

9.64255

9.617611029

2009

4.6629

9.99428

9.981617827

2008

4.6881

10.03215

10.02049645

2007

4.8335

10.25025

10.24330591

2006

4.9099

10.3648

10.35957058

2005

4.6476

9.97134

9.958039724

2004

4.8482

10.27234

10.26576675

2003

4.7722

10.15826

10.14955663

2002

4.6609

9.99133

9.978588219

2001

4.8234

10.23506

10.22784829

2000

5.197

10.79544

10.79222813

1999

5.1426

10.71391

10.71084462

1998

4.8213

10.23202

10.22475288

1997

4.8064

10.20958

10.20190305

1996

5.0661

10.59908

10.59579697

1995

4.8842

10.32624

10.32048931

1994

4.9593

10.43894

10.43455099

1993

4.6356

9.95346

9.939643803

1992

4.1256

9.18836

9.139453187

1991

4.3194

9.47913

9.446649243

1990

4.2933

9.43991

9.405442001

1989

4.1534

9.23008

9.183776802

1988

4.1526

9.22895

9.182576395

1987

4.7624

10.14366

10.13464762

1986

4.4302

9.64531

9.620479487

1985

4.3534

9.53013

9.500131794

1984

4.2777

9.41654

9.380856641

1983

4.3328

9.49926

9.467772054

1982

4.303

9.45448

9.420763484

1981

3.9977

8.99659

8.934643423

1980

4.2914

9.43706

9.402442737

1979

4.4937

9.74057

9.719583169

1978

4.1406

9.21091

9.163423382

1977

4.4841

9.72621

9.704666477

1976

3.9921

8.9882

8.925640812

1975

4.2234

9.33517

9.295055739

1974

4.1329

9.19939

9.151176325

1973

4.2256

9.33843

9.298496753

1972

3.6877

8.53151

8.430114661

1971

3.9019

8.85283

8.779901481

1970

4.3582

9.53726

9.507593059

1969

4.0885

9.13273

9.080224319

1968

3.42

8.12998

7.98489122

1967

3.7654

8.64806

8.557632809

1966

3.9974

8.99607

8.934087117

1965

3.9926

8.98893

8.926421947

1964

4.0536

9.08044

9.024420389

1963

3.9519

8.92778

8.86070202

1962

4.4871

9.73068

9.70931397

1961

4.5761

9.86421

9.847615261

1960

4.3226

9.48389

9.451649614

1959

4.4197

9.62956

9.604061418

1958

4.3176

9.47642

9.443812655

1957

4.284

9.42606

9.390875979

1956

4.4933

9.73992

9.718900369

1955

4.526

9.78895

9.769753577

1954

4.4039

9.60581

9.579272037

1953

4.6675

10.00123

9.988749833

1952

4.1944

9.29161

9.24899382

1951

4.5664

9.84959

9.832512944

1950

4.9205

10.38078

10.37575626

1949

4.6644

9.99666

9.984058775

1948

4.642

9.96298

9.949431313

1947

4.4217

9.63262

9.607252457

1946

4.0455

9.06829

9.011436281

1945

4.2057

9.30856

9.266920677

1944

4.1788

9.26817

9.224167423

1943

3.8844

8.82661

8.751553706

1942

4.0982

9.14732

9.095777231

1941

4.5277

9.79156

9.772458909

1940

4.7221

10.08314

10.07275964

1939

4.8946

10.34193

10.33640145

1938

4.9724

10.45861

10.45440785

1937

4.9582

10.4373

10.43290055

1936

5.2509

10.87634

10.87275745

1935

4.9479

10.42191

10.41735229

1934

4.9715

10.4573

10.45309002

1933

4.5127

9.76901

9.749085092

1932

4.9238

10.38566

10.38068666

1931

4.8674

10.30107

10.29495503

1930

5.6354

11.45309

11.4402923

1929

5.2526

10.87884

10.87524025

1928

4.7485

10.12274

10.11327367

1927

4.8024

10.20356

10.19576453

1926

4.7034

10.05516

10.04409445

1925

5.1894

10.78404

10.78086417

1924

4.7937

10.19057

10.18252189

1923

4.8389

10.2584

10.25159603

1922

4.9042

10.35625

10.35091208

1921

4.8766

10.31489

10.30897333

1920

4.3535

9.53018

9.500190213

1919

3.8842

8.82628

8.751197837

1918

3.6111

8.41664

8.303691707

1917

3.577

8.36553

8.247201123

1916

3.5522

8.32832

8.205985691

1915

3.839

8.75846

8.67773386

1914

3.9001

8.85017

8.777028191

1913

4.0691

9.10366

9.049217854

1912

4.5802

9.87032

9.853922514

1911

4.5523

9.82839

9.810588717

1910

3.8585

8.78778

8.709530656

1909

3.5682

8.35223

8.23248619

1908

3.3991

8.09865

7.949753065

1907

3.5945

8.39175

8.276208905

1906

3.6832

8.52476

8.422707096

1905

3.9483

8.9225

8.855020902

1904

3.8072

8.71085

8.626015118

1903

4.5396

9.80945

9.790987214

1902

4.5168

9.77514

9.755439462

1901

5.0976

10.64642

10.64328835

1900

5.3851

11.07767

11.07214784

1899

5.4791

11.21859

11.21088496

1898

5.1497

10.72448

10.72140392

1897

6.1339

12.20081

12.16019681

1896

6.2487

12.37309

12.32371431

1895

6.8593

13.28892

13.17929756

1894

7.6555

14.48323

14.26369485

1893

6.696

13.04394

12.95259388

1892

5.2458

10.86867

10.86512532

1891

5.8506

11.77591

11.75320437

1890

6.1883

12.28251

12.23784665

1889

6.1458

12.21868

12.17719232

1888

4.9631

10.44468

10.44035115

1887

6.5734

12.86007

12.78143191

1886

5.6707

11.50599

11.49179173

1885

5.3197

10.9796

10.97519937

1884

5.568

11.35201

11.34162992

1883

5.857

11.78552

11.76247384

1882

5.4041

11.10612

11.10020934

1881

5.1499

10.72481

10.7217299

1880

4.7616

10.14245

10.13341609

1879

5.2926

10.93885

10.93481193

1878

5.1552

10.73285

10.72976579

1877

5.6649

11.49738

11.48341183

1876

5.8147

11.72211

11.7012852

1875

6.1537

12.23061

12.18854209

1874

7.4844

14.22663

14.03348219

1873

8.9883

16.48243

16.01101468

1872

9.284

16.92598

16.38854802

1871

10.636

18.954

18.07390475