This repository contains Python code to compute the Bayesian average of Steam games, developers, and publishers.

• Install the latest version of Python 3.X.

• Install the required packages:

pip install -r requirements.txt

• Call the Python script. SteamSpy data will be automatically downloaded through an API.

python compute_bayesian_average.py

Formulas are shown on the Wiki.

The higher the ratio of positive reviews, and the more reviews, the more likely a game, a developer or a publisher is acclaimed.

The higher the game scores, and the more released games, the more likely a developer or a publisher is reliable.

The most acclaimed its most reviewed games, and the more reliable, the more likely a developer or a publisher is established.

Results are shown in the Wiki for:

• the most acclaimed games,
• the most acclaimed, the most reliable, and the most established developers,
• the most acclaimed, the most reliable, and the most established publishers.

• Wikipedia: Bayesian Average
• the Steam250 website which updates rankings every day.
• Torn's "Best of Steam" website which updates rankings every day and allows custom ranking formulas.

• Using average values obtained on September 3, 2023 for the prior:

const C = 1117 ;  // prior: average #reviews
const m = 0.756 ; // prior: average score
const n = game.votes ;
return (C*m + game.positiveVotes) / (C+n) ;

• Using median values obtained on September 3, 2023 for the prior:

const C = 17 ;    // prior: median #reviews
const m = 0.822 ; // prior: median score
const n = game.votes ;
return (C*m + game.positiveVotes) / (C+n) ;

• For comparison, replicating SteamDB's formula, which does not use Bayesian average::

const C = 1 ;    // offset for #reviews
const m = 0.50 ; // middle point for score
const n = game.votes ;
const p = game.positiveVotes / n ;
const t = (C+n) ** Math.log10(m) ;
return t*m + (1-t)*p ;

The current algorithm relies solely on SteamSpy data. In case SteamSpy API stops providing the numbers of positive and negative reviews, data from SteamDB could be merged with SteamSpy data.

• To download data from SteamDB, first sign-in with your Steam account.

Once you are signed-in, make sure to view all games, then copy and paste the whole table as text into data/steamdb.txt.