Q. What are Batting/Pitching Park Factors?
Batting Park Factor (BatPF) and Pitching Park Factor (PitPF) attempt to quantify how a team's batting and pitching
statistics are influenced by the configuration, altitude, and climate of its home ballpark.

BatPF > 100 implies that the team's batters take advantage of their home ballpark and would score (BatPF-100)% more runs
at home than they would in a theoretical "league-average" ballpark.
BatPF < 100 suggests that the team's batters are penalized by their home ballpark and would score (100-BatPF)% less runs
at home than they would in the "league-average" park.

PitPF < 100 implies that the team's pitchers take advantage of their home ballpark and would allow (100-PitPF)% less runs
from being scored at home than they would in a theoretical "league-average" ballpark.
PitPF > 100 suggests that the team's pitchers are penalized by their home ballpark and would allow (PitPF-100)% more runs
at home than they would in the "league-average" park.


Q. How are Batting/Pitching Park Factors computed?
Park factor scores displayed for a given year are actually the windowed average of (up to 5) preceding single-season marks.
Windowed averages are used to compensate for seasonal variations in performance as well as personnel.
Single-season park factors are computed via the following set of definitions and equations:

Definitions:
   HW: Home Wins
   HL: Home Losses
  HRS: Runs Scored at Home
  HRA: Runs Allowed at Home

   RW: Road Wins
   RL: Road Losses
  RRS: Runs Scored on Road
  RRA: Runs Allowed on Road

  RAL: Total Runs Scored per Game (league-wide average)
   NT: Number of Teams in League (12)

Equations:
1)   IF - Initial Factor
        = (HRS+HRA) / (RRS+RRA)
2)  IPC - Innings Pitched Corrector
        = [18.5 - (HW/(HW+HL))] / [18.5 - (RL/(RW+RL))]
3)   TR - Team Rating
        = IF / IPC
4)  OPC - Other Parks Corrector
        = NT / (NT-1+TR)
5)   SF - Scoring Factor
        = OPC * TR
6)  SF1 - Scoring Factor of Other Teams
        = 1 - [(SF-1)/(NT-1)]
7)  RHT - Runs per Game Scored At Home
        = HRS / (HW+HL)
8)  RAT - Runs per Game Scored On Road
        = RRS / (RW+RL)
9)  OHT - Runs per Game Allowed At Home
        = HRA / (HW+HL)
10) OAT - Runs per Game Allowed On Road
        = RRA / (RW+RL)

Calculate TBR and TPR for 3 iterations, initially setting both TBR=1 and TPR=1 for first iteration.
11) TBR - Team Batting Rating
        = [ ((RAT/SF1) + (RHT/SF)) * (1 + ((TPR-1)/(NT-1)) ) ] / RAL
12) TPR - Team Pitching Rating
        = [ ((OAT/SF1) + (OHT/SF)) * (1 + ((TBR-1)/(NT-1)) ) ] / RAL

13) BatPF - Batting Park Factor
          = (SF+SF1) / [ 2 * ( 1 + ((TPR-1)/(NT-1)) ) ]
14) PitPF - Pitching Park Factor
          = (SF+SF1) / [ 2 * ( 1 + ((TBR-1)/(NT-1)) ) ]