Glossary - Seamheads Negro Leagues Database

# Glossary

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Baseball Gauge Wins Above Replacement (gWAR)

## Replacement Level

Replacement level is set at a .294 winning percentage in order to maintain continuity with Baseball-Reference's version of WAR (rWAR).

## Pythagorean Winning Percentage

The PythagenPat method is used when converting runs to wins and also uses .285 as the exponent in the formula.

## Offense

The Offensive component uses Base Runs to estimate a player's value (in runs) above/below average. Individual player's Base Runs are calculated using the theoretical team method.

#### WAA (Wins Above Average) Formula

LgR/G = League's Runs/Game
RAA = Player's Base Runs above average
G = Player's games played

TmR/G = LgR/G + RAA / G
exponent = (TmR/G + LgR/G)^.285

Offensive WAA = ((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G

#### WAR (Wins Above Replacement) Formula

LgR/G = League's Runs/Game
RAA = Player's Base Runs above average
RAR = Player's Base Runs above replacement
G = Player's games played
oWAA = Offensive Wins Above Average

TmR/G = LgR/G + (RAA - RAR) / G
exponent = (TmR/G + LgR/G)^.285

Offensive WAR = oWAA - ((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G

#### WAG (Wins Above Greatness) Formula

oWAR = Offensive Wins Above Replacement
PA = Player's plate appearances

Offensive WAG = oWAR - (PA / 600) * 3

## Fielding

The Fielding component uses a multi-year average of Defensive Regression Analysis (DRA) to estimate a player's value (in runs saved) above/below average. DRA was created by Michael Humphreys and its method is described in the book Wizardry.

#### Formula

LgR/G = League's Runs/Game
DRA = Player's runs saved above average (from all positions)
G = Player's games played

TmR/G = LgR/G + DRA / G
exponent = (TmR/G + LgR/G)^.285

Fielding WAA = ((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G

In order ot maintain continuity, Baseball-Reference's positional adjustments are used. Positional adjustments are NOT INCLUDED in offensive and fielding WAR.

#### Formula

LgR/G = League's Runs/Game
posR = Player's positional adjustment in runs (from all positions)
G = Player's games played

TmR/G = LgR/G + posR / G
exponent = (TmR/G + LgR/G)^.285

Positional Adjustment = ((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G

## Pitching

Pitching WAR is based on runs allowed with an adjustment for a team's fielders.

#### WAA (Wins Above Average) Formula

LgR/G = League's Runs/Game
RAA = Player's runs allowed above average (with positive being better)
G = Player's games played

TmR/G = LgR/G + RAA / G
exponent = (TmR/G + LgR/G)^.285

Pitching WAA = (((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G)

#### WAR (Wins Above Replacement) Formula

LgR/G = League's Runs/Game
RAA = Player's runs allowed above average (with positive being better)
RAR = Player's runs allowed above replacement (with positive being better)
G = Player's games played
pWAA = Pitching Wins Above Average

TmR/G = LgR/G + (RAA - RAR) / G
exponent = (TmR/G + LgR/G)^.285

Pitching WAR = pWAA - ((TmR/G^exponent / (TmR/G^exponent + LgR/G^exponent)) - .5) * G

#### WAG (Wins Above Greatness) Formula

pWAR = Pitching Wins Above Replacement
IP = Player's innings pitched

Pitching WAG = pWAR - (IP / 525) * 2.5