Changelog#

Version Numbering#

penaltyblog follows the SemVer versioning guidelines. For more information, see semver.org

v1.1.0 (2025-03-15)#

Performance Enhancements#

  • Rewrote Dixon-Coles model using Cython, achieving approximately 250x speed improvement.

  • Rewrote Poisson model using Cython, achieving approximately 250x speed improvement.

  • Implemented Negative Binomial Goals Model in Cython for enhanced performance.

  • Added high-performance Cython implementation of the Bivariate Poisson Goals Model based on Karlis & Ntzoufras.

  • Introduced Cython implementation of the Bivariate Weibull Count Copula Goals Model (Boshnakov et al. paper).

  • Developed Pi Ratings System (Constantinou paper).

  • Migrated ranked probability score functions to Cython for improved speed.

Package Updates#

  • Temporarily removed Stan-based models due to dependency management challenges. Investigating improved packaging strategies for future reintegration.

  • Temporarily removed Rue and Salvesen model pending revision to accurately reflect its intended methodology (previously implemented as a hybrid Dixon-Coles variant).

Documentation Improvements#

  • Updated and expanded model examples in the documentation.

  • Enhanced type hints throughout the package for improved compatibility with mypy.

  • Updated documentation to pydata Sphinx theme.

CI/CD and Testing#

  • Expanded GitHub Actions workflows to perform unit tests across all supported Python versions.

  • Extended GitHub Actions workflows to perform unit tests on Windows, macOS, and Linux.

  • Configured GitHub Actions to automatically build wheels for all supported Python versions across Windows, macOS, and Linux.

—

v1.0.4 (2025-01-10)#

Package Updates#

  • Moved Stan code to separate files to prevent access denied issues on Windows.

—

v1.0.3 (2024-12-19)#

Bug Fixes#

  • Fixed bug in how the Bayesian models indexed teams in the predict function.

  • Goals models now only predict individual team names rather than iterables of team names, fixing compatibility issues between different sequence objects.

—

v1.0.2 (2024-12-18)#

Bug Fixes#

  • Updated how the Bayesian models handle the Stan files to prevent access denied issues on Windows.

—

v1.0.1 (2024-12-13)#

Improvements#

  • Updated install_stan to install the C++ toolchain on Windows if required.

—

v1.0.0 (2024-12-12)#

Performance Enhancements#

  • Removed pymc as a dependency.

  • Optimized RPS calculation.

  • Optimized ELO code.

  • Optimized Kelly Criterion code.

  • Updated FootballProbabilityGrid to store its internal matrix as a NumPy array.

Model Updates#

  • Rewrote BayesianHierarchicalGoalModel in Stan instead of pymc, updating the prediction method to integrate over the posterior rather than sampling the mid-point.

  • Rewrote BayesianRandomInterceptGoalModel in Stan, improved the random intercept, and updated the prediction method.

  • Rewrote BayesianBivariateGoalModel in Stan for better convergence and updated the prediction method.

  • Added BayesianSkellamGoalModel for predicting football match outcomes using the Skellam distribution.

Package Updates#

  • Added support for Python 3.13.

  • Removed obsolete SoFifa and ESPN scrapers.

  • Updated all example notebooks.

  • Increased unit test coverage.

  • Added CI/CD workflows.

  • Removed Poetry from the build step.

  • Updated documentation.

  • Added type hinting to Colley and Massey classes.

—

v0.8.1 (2023-09-31)#

Bug Fixes#

  • Changed FBRef born column to Int64 dtype to allow NULL values.

—

v0.8.0 (2023-08-31)#

New Features#

  • Added initial Backtest framework for backtesting betting strategies.

  • Added function to calculate the Kelly Criterion.

  • Added class for calculating Elo ratings.

Bug Fixes#

  • Fixed bug in FBRef scraper for player age and year of birth.

  • All goal models can now accept iterables as team inputs.

  • Fixed mapping of Belgium leagues in the FootballData scraper.

—

v0.7.0 (2023-03-13)#

New Features#

  • Added FBRef scraper.

Package Updates#

  • Minimum Python version supported is now Python 3.8.

—

v0.6.1 (2023-01-06)#

Bug Fixes#

  • Tweaked Understat scraper to avoid bot detection.

—

v0.6.0 (2022-12-02)#

New Features#

  • Added goal_expectancy function.

  • Added Bayesian Random Intercept Model.

Performance Enhancements#

  • Tweaked pymc settings for Bayesian goal models to improve speed.

Bug Fixes#

  • Fixed bug in Bayesian Bivariate Goals Model.

  • Fixed bug in FootballData scraper where a null value was breaking the index column.

—

v0.5.1 (2022-11-03)#

Bug Fixes#

  • Fixed bug in goal models when printing an instance before fitting it.

  • Fixed bug in Bayesian goal models’ weighted decay.

  • Fixed default value of xi in dixon_coles_weights to 0.0018.

—

v0.5.0 (2022-10-11)#

New Features#

  • Added get_player_season and get_player_shots to Understat scraper.

  • Added Bayesian Hierarchical Goal Model.

  • Added Bayesian Bivariate Poisson Goal Model.

  • Added Bayesian Random Intercept Poisson Goal Model.

Bug Fixes#

  • get_fixtures in Understat scraper now only returns completed fixtures (consistent with FootballData scraper).

  • Fixed bug in FootballData scraper for older seasons missing the Time column.

Package Updates#

  • Added SoFifa scraper.

  • Added compatibility for Python 3.7.

—

v0.4.0 (2022-08-08)#

General Improvements#

  • General bug fixes.

  • Reorganized internal package structure.

  • Added unit tests.

  • Added documentation and uploaded to ReadTheDocs.

New Features#

  • Added FPL scraper.

  • Added FPL optimizer.

  • Added ESPN scraper.

  • Added Understat scraper.

  • Added pre-commit checks to repository.

  • Added both-teams-to-score probability to football goals models.

  • Refactored FootballData scraper for consistency with other scrapers.

  • Refactored Club Elo scraper for consistency with other scrapers.

Performance Enhancements#

  • Refactored Colley ratings and Massey ratings for consistency.

  • Updated example notebooks and included them in documentation.