trueskill
The video game rating system
Decision gist · record as of 2026-08-14
No for new projects. The package is abandoned (last release 2018-09-07) with no active maintenance, high install friction (source-only), and classifiers that predate modern Python versions. Use it only if you are maintaining existing code already depending on it, or for educational exploration of the TrueSkill algorithm. For new competitive rating systems, consider actively maintained alternatives.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 2.7 or Python 3.4+; no external runtime dependencies but source distribution requires build tools.
- High install friction due to source-only distribution (tarball).
- Maintenance status is abandoned—last release was 2018-09-07, over 2898 days ago.
License · maintenance · safety
BSD (permissive) — BSD license is permissive; you may use, modify, and distribute the package freely with minimal restrictions.
last release 2018-09-07 (2898 days)
0 known vulnerabilities (OSV.dev, 2026-08-14) · 200,242 downloads/mo, #9,697 on PyPI
Alternatives
Verify before relying
from trueskill import Rating, quality_1vs1, rate_1vs1
alice, bob = Rating(25), Rating(30)
if quality_1vs1(alice, bob) < 0.50:
print('Match fairness low')
alice, bob = rate_1vs1(alice, bob)- Whether the package builds and runs correctly on modern Python versions (3.8+) despite classifiers stopping at 3.7.
- Whether the algorithm implementation matches current TrueSkill specifications or if it has known mathematical limitations.
- Community adoption and whether alternatives have superseded it for new projects.
What it is and what it does
TrueSkill is a Bayesian skill rating system developed by Microsoft and used on Xbox Live to rank and match players. It provides functions to initialize player ratings, compute match quality (fairness), and update ratings after match outcomes. The package exports a simple API: Rating objects represent player skill, quality_1vs1 estimates match fairness, and rate_1vs1 updates ratings after a match result.
The package has no runtime dependencies and works across Python 2.7 and Python 3.4+. However, it is distributed as a source tarball only and has not been maintained since 2018, with no recent updates or security patches. It is suitable for hobby projects, educational use, or legacy systems already using it, but carries the risk of incompatibility with future Python versions and lack of maintainer support.
Use it for
- Implement player ranking in turn-based or multiplayer games where Bayesian skill estimation is preferred over simpler Elo-style systems.
- Compute match fairness before pairing players to avoid lopsided matchups in competitive gaming.
- Educational projects studying Bayesian inference and skill rating algorithms.
- Legacy systems or hobby projects already integrated with TrueSkill that do not require active maintenance.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
No for new projects.
The package is abandoned (last release 2018-09-07) with no active maintenance, high install friction (source-only), and classifiers that predate modern Python versions. Use it only if you are maintaining existing code already depending on it, or for educational exploration of the TrueSkill algorithm. For new competitive rating systems, consider actively maintained alternatives.
Install
trueskill on PyPI
Before you install
High install friction due to source-only distribution (tarball). Maintenance status is abandoned—last release was 2018-09-07, over 2898 days ago. No active development or security updates.
Requires Python 2.7 or Python 3.4+; no external runtime dependencies but source distribution requires build tools.
License in practice
BSD license is permissive; you may use, modify, and distribute the package freely with minimal restrictions.
Quickstart
from trueskill import Rating, quality_1vs1, rate_1vs1
alice, bob = Rating(25), Rating(30)
if quality_1vs1(alice, bob) < 0.50:
print('Match fairness low')
alice, bob = rate_1vs1(alice, bob)Verify before relying
- Whether the package builds and runs correctly on modern Python versions (3.8+) despite classifiers stopping at 3.7.
- Whether the algorithm implementation matches current TrueSkill specifications or if it has known mathematical limitations.
- Community adoption and whether alternatives have superseded it for new projects.
Package facts
| License | BSD permissive |
| Python support | Supports the current Python release >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.* |
| Install friction | High. Source build required |
| Runtime dependencies | None |
| Maintenance | Abandoned 2,898 days since the last release |
| First released | |
| Downloads | 200,242 / month, #9,697 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 4 - BetaIntended Audience :: DevelopersIntended Audience :: Science/ResearchLicense :: OSI Approved :: BSD LicenseOperating System :: OS IndependentProgramming Language :: PythonProgramming Language :: Python :: 2Programming Language :: Python :: 2.7Programming Language :: Python :: 3Programming Language :: Python :: 3.4Programming Language :: Python :: 3.5Programming Language :: Python :: 3.6Programming Language :: Python :: 3.7Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: JythonProgramming Language :: Python :: Implementation :: PyPyTopic :: Games/EntertainmentTopic :: Scientific/Engineering :: Mathematics |
Evidence: trueskill-0.4.5.tar.gz
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