The Alliance Team Rating System
How the Alliance Team Rating System Works
- The Alliance Team Rating System represents your team’s current rating, similar to RPI in college softball.
- The Alliance Team Rating uses the elo Rating System.
- Teams exchange rating points based on the outcome of games.
- A team that performs better than expected gains team rating points.
- A team that performs worse than expected loses team rating points.
- Teams are incentivized to play stronger opponents.
- Stronger teams must consistently beat weaker teams to maintain or improve their team rating.
- Weaker teams can improve their team rating by playing stronger teams, even without winning many games.
League Division Defaults
- Super Division teams and 10U teams start with a default team rating of 1600.
- Champions Division teams start with a default team rating of 1400.
Playing Opponents who are not recognized in the Alliance System
- Sometimes you will play an opponent that is not registered with the Alliance Fastpitch or does not have enough registered players for our system to recognize that team.
- If your opponent is not recognized as an Alliance Team, their initial Team Rating will default to your Team Rating
- Example: Team A and Team B are registered with the Alliance and have a Team Rating. Team C is not registered with the Alliance so their rating for the tournament will default to their opponents.
- Team A has a rating of 1634
- Team B has a rating of 1732
- Team C is not recognized as an Alliance Team
- Team A (1634) vs Team C (1634)
- Team B (1732) vs Team C (1732)
- Team A (1634) vs Team B (1732)
- Example: Team A and Team B are registered with the Alliance and have a Team Rating. Team C is not registered with the Alliance so their rating for the tournament will default to their opponents.
Alliance Team Rating Carryover Rules
If your team renews its membership (keeping the same Team ID), your previous season’s rating carries over under these conditions:
- Same Age & League Division: Retain 75% of your previous rating.
- Same League Division, Different Age: Retain 25% of your previous rating.
- If a team’s final rating was below the League Division Default, it resets to the default for the next season:
- Example: If a Super Division team ended with a 1580 rating in 2024, it starts at 1600 in 2025.
- If a team changes League Divisions, the rating resets to that division’s default:
- Super Division → 1600
- Champions Division → 1400
Why Renewing Your Team Matters
- Retaining the same Team ID ensures historical data continuity.
- Carryover rules provide teams with more accurate starting ratings instead of resetting every season.
- Helps new teams rise faster in the rankings.
- If a new team beats a high-rated team, they gain more points earlier.
- If a new team loses to a high-rated team, they don’t lose as many points.
What is the Alliance Team Rating System Used For?
Your Alliance Team Rating determines your team’s placement in:
- League & National leaderboards
- League rankings appear on each Alliance Member League website and your Team Profile.
- National rankings appear on the Alliance National Leaderboards.
- League Championship Seeding
- AFCS Seeding Committee Evaluations
- (Note: Elo rating is only one factor in the seeding process. Click here to review the full process.)
Earning Points
- OFFICIAL SCORING: You must stream & score the game in AthletesGoLive (AGL) in order to receive points.
- EVENT: Use the AGL EVENT ID to identify the tournament you are playing in.
- OPPONENT: Ensure you select the correct opponent AGL ID when scheduling your games within AGL. This will help with the accuracy of the points awarded based on the matchup.
- If using team name you need to confirm the AGL ID next to the team name is correct to ensure we are accurately capturing your points based on your opponent.
- Reference the ALLIANCE TEAM LIST or your LEAGUE TEAM LIST to easily find your opponent's AGL ID.
- Enter the opponent's ALLIANCE ID if they do not have an AGL ID.
- TIE BREAKER (for teams facing off with the same rating):
Strength of Schedule > Strength of Victory > Runs Against > Runs Scored - The amount of points awarded for each game is based on the win probability of the game. If you are expected to win (i.e. your team has a higher rating than your opponent) you will receive less points for a win. If you are expected to lose, but end up winning, you will receive more points for a win.
Elo Formula
The Alliance Rating System follows the Elo formula:
$$ \text{New Rating} = \text{Current Rating} + K \times (\text{Actual Score} - \text{Expected Score}) $$
Where:
- Current Rating is a team's Elo rating before the game.
- K-factor determines the maximum adjustment per game:
- Bracket games: \( K = 32 \)
- All other games (pool play, showcase, etc.): \( K = 16 \)
- Actual Score (\( S \)):
- \( S = 1 \) if the team wins.
- \( S = 0.5 \) for a tie.
- \( S = 0 \) if the team loses.
- Expected Score (\( E \)) is calculated based on the opponent's rating:
$$ E = \frac{1}{1 + 10^{\left(\frac{\text{Opponent Rating} - \text{Team Rating}}{400}\right)}} $$
- If a team wins: it gains more points if it defeats a higher-rated opponent and fewer points if it defeats a lower-rated opponent.
- If a team loses: it loses more points if it was expected to win and fewer points if it was expected to lose.
- If a weaker team upsets a stronger team: the rating adjustment is larger.
Elo Rating Calculation Example
In this example, we assume:
- Team A is a strong team with an average Elo rating of 1800.
- Team B is a weaker team with an average Elo rating of 1500.
- The game type is a pool game, meaning the K-factor is 16.
Step 1: Expected Score Calculation
The expected score formula is:
$$ E_A = \frac{1}{1 + 10^{\left(\frac{R_B - R_A}{400}\right)}} $$
Substituting the values:
$$ E_A = \frac{1}{1 + 10^{\left(\frac{1500 - 1800}{400}\right)}} $$
$$ E_A = \frac{1}{1 + 10^{-0.75}} = \frac{1}{1 + 0.1778} = \frac{1}{1.1778} \approx 0.849 $$
For Team B:
$$ E_B = 1 - E_A = 1 - 0.849 = 0.151 $$
Step 2: Elo Rating Adjustment
The new rating is calculated using:
$$ \text{New Rating} = \text{Current Rating} + K \times (\text{Actual Score} - \text{Expected Score}) $$
Scenario 1: Team A Wins
If Team A wins (\( S_A = 1 \), \( S_B = 0 \)):
$$ \Delta R_A = 16 \times (1 - 0.849) = 16 \times 0.151 = 2.42 $$
$$ \Delta R_B = 16 \times (0 - 0.151) = 16 \times (-0.151) = -2.42 $$
Result: Team A gains +2.4 points, and Team B loses -2.4 points.
Scenario 2: Team B Wins
If Team B wins (\( S_A = 0 \), \( S_B = 1 \)):
$$ \Delta R_A = 16 \times (0 - 0.849) = 16 \times (-0.849) = -13.58 $$
$$ \Delta R_B = 16 \times (1 - 0.151) = 16 \times 0.849 = 13.58 $$
Result: Team B gains +13.6 points, and Team A loses -13.6 points.
Final Thoughts
Because Team A is expected to win, the Elo adjustment is small when they do win. However, if Team B pulls off an upset, the Elo adjustment is much larger to reflect the unexpected outcome.
Why Elo?
- Most commonly used sports rating system
- Used by FIFA
- Used by Sagarin
- NFL/MLB/NBA/NHL
- College sports
- Used by 538.com
- NFL/MLB/NBA/NHL
Alliance Power Points
- Alliance Power Points (APP) will be awarded when traveling to a different League’s territory or when playing a traveling team from a different League in a Points event
- Alliance Power Points will be awarded based on the following:
| 3 | Travelling Team Tie | 2 | Neutral Ground Tie | 2 |
|---|---|---|---|
| Traveling Team Loss | 1 | Neutral Ground Loss | 1 |
| Local Team Wins | 2 | ||
| Local Team Tie | 1 |
Questions?
Please contact info@thealliancefastpitch.com with any questions about Alliance Team Rating System.