Pythagorean Win Calculator Formula

Understand the math behind the pythagorean win calculator. Each variable explained with a worked example.

Formulas Used

Expected Win %

exp_win_pct = round(expected_win_pct * 1000) / 1000

Expected Wins

expected_wins = round(expected_win_pct * games_played * 10) / 10

Expected Losses

expected_losses = round((1 - expected_win_pct) * games_played * 10) / 10

Avg Point Differential

pts_per_game_diff = round((points_scored - points_allowed) / games_played * 10) / 10

Variables

VariableDescriptionDefault
points_scoredTotal Points Scored750
points_allowedTotal Points Allowed680
games_playedGames Played82
exponentPythagorean Exponent14
expected_win_pctDerived value= pow(points_scored, exponent) / (pow(points_scored, exponent) + pow(points_allowed, exponent))calculated

How It Works

How the Pythagorean Win Formula Works

Formula

Expected Win % = PF^exp / (PF^exp + PA^exp)

Where PF = Points For, PA = Points Against, and exp is the Pythagorean exponent.

Typical Exponents

  • MLB: 1.83
  • NFL: 2.37
  • NBA: 14
  • NHL: 2.05
  • Teams that significantly outperform their Pythagorean expectation often regress toward the expected record in subsequent seasons.

    Worked Example

    NBA team: 750 points scored, 680 allowed through 82 games (exponent 14).

    points_scored = 750points_allowed = 680games_played = 82exponent = 14
    1. 01Win % = 750^14 / (750^14 + 680^14)
    2. 02This evaluates to approximately 0.769
    3. 03Expected wins = 0.769 * 82 = 63.1 wins
    4. 04Expected losses = 82 - 63.1 = 18.9
    5. 05Avg point diff = (750 - 680) / 82 = 0.9 per game

    Frequently Asked Questions

    Why different exponents for different sports?

    Higher-scoring sports like basketball need larger exponents because individual game outcomes are less random. Baseball, with fewer runs, uses a smaller exponent.

    What does it mean to over- or under-perform Pythagorean?

    A team winning more than expected may be winning close games at an unsustainable rate (luck in clutch situations). They often regress the next year.

    How accurate is the Pythagorean formula?

    It is remarkably accurate over a full season. Expected wins typically predict actual wins within 2-4 games for most teams.

    Ready to run the numbers?

    Open Pythagorean Win Calculator