Best Connect 4 Books and Papers — Reviewed
Connect Four’s book canon is small but unusually high-quality. Below are 7 essential reads, from the original 1988 solver thesis to the modern open tutorials. Honest pros, honest cons.
Unlike chess or Go, Connect Four does not have a sprawling published library. The game was solved in 1988, which truncated the appetite for opening encyclopaedias and championship monographs. What exists instead is a small, dense canon — a handful of academic texts, one mass-market book, a few online tutorials — that genuinely covers the field. Read in roughly the order below and you will know more about Connect Four than 99% of the people who play it.
The Essential Reading List
A Knowledge-Based Approach of Connect-Four — The Game is Solved: White Wins
Louis Victor Allis · 1988 · ★★★★★ (5.0/5)
Allis's master's thesis — the foundational document of modern Connect Four theory. Establishes the first published weak solution by hand-coding nine strategic rules (claimeven, baseinverse, vertical, aftereven, lowinverse, highinverse, baseclaim, before, specialbefore) that together prove the first player can force a win from the centre. Every modern solver descends from the framework set out here.
Pros
- The original proof — every cited Connect Four solution traces back to this
- Free PDF available online
- Written for a technical audience but legible to a careful hobbyist
Cons
- Academic format — not a casual read
- Pre-modern notation in places
- No puzzle sets
Practice what you read in the browser at play4row →
The Complete Book of Connect-4: History, Strategy, Puzzles
James D. Allen · 2010 · ★★★★★½ (4.5/5)
The closest thing to a popular-audience Connect Four book. Combines a narrative history of the game with strategic principles, opening theory, and a puzzle set. Allen, who solved the game independently in October 1988, brings the rare combination of solver-author technical depth and a clear plain-English writing style.
Pros
- Plain-English explanations of perfect-play principles
- Covers history, strategy, and puzzles in one volume
- Author is one of the original solvers
Cons
- Out of print in some markets — used copies on Amazon vary in price
- Smaller puzzle set than dedicated training books
- Some printings have layout issues with the diagrams
Practice what you read in the browser at play4row →
Searching for Solutions in Games and Artificial Intelligence
Louis Victor Allis · 1994 · ★★★★★½ (4.5/5)
Allis's PhD dissertation, generalising the methodology of the 1988 Connect Four work to a wider class of solved and partially-solved combinatorial games (Qubic, Go-Moku, others). Connect Four is not the central focus, but the chapters that revisit it deepen and clarify the original proof.
Pros
- Extends the 1988 framework with five more years of refinement
- Useful for understanding why the Connect Four solution works the way it does
- A landmark text in computational game theory
Cons
- Quite dense — assumes academic mathematical comfort
- Connect Four is one chapter of many
Practice what you read in the browser at play4row →
Connect Four — Online Resource and Database (web)
John Tromp · 1995 · ★★★★★½ (4.5/5)
Not a book strictly speaking, but the canonical online research archive for Connect Four — strong-solver source code, the bit-packed endgame databases, position-count enumerations, and write-ups of the methodology. The de-facto reference for anyone implementing a Connect Four solver.
Pros
- Source code for a reference strong solver
- Endgame database that other tools verify against
- Still actively maintained in 2026
Cons
- Functional rather than polished presentation
- Assumes you can read C and understand bitboards
Practice what you read in the browser at play4row →
One Jump Ahead: Computer Perfection at Checkers
Jonathan Schaeffer · 2008 · ★★★★★½ (4.5/5)
Schaeffer's memoir of solving Checkers. Connect Four is referenced repeatedly as part of the broader story of solved games in the 1980s–2000s, with Allis's work cited as one of the early modern game-solving milestones. Recommended context if you want to understand where Connect Four sits in the larger arc of computational game-solving.
Pros
- Beautifully written by one of the field's leading figures
- Sets Connect Four solving in its historical context
- Accessible to non-technical readers
Cons
- Connect Four is not the central topic
- Skip if you only want Connect Four content
Practice what you read in the browser at play4row →
Solving Connect 4 — Step-by-Step Tutorial Series (web)
Pascal Pons · 2017 · ★★★★★½ (4.5/5)
A long-form open-web tutorial that walks through building a Connect Four solver from naïve minimax up through a transposition-table-and-opening-book reference implementation. Free, well-illustrated, and one of the best self-study resources for anyone wanting to understand how a perfect-play engine actually works.
Pros
- Free and openly available
- Step-by-step build-up from textbook minimax to a state-of-the-art solver
- Companion source code on GitHub
Cons
- Web-only — no print edition
- Assumes intermediate programming comfort
Practice what you read in the browser at play4row →
Fundamentals of Game Design (Connect Four chapter)
Ernest Adams · 2013 · ★★★★ (4.0/5)
A standard university-level games-design textbook. The chapter on abstract strategy games uses Connect Four as a worked example for explaining state-space size, branching factor, and the relationship between game length and solvability. Useful background reading rather than a strategy book.
Pros
- Sets Connect Four in the broader landscape of game design
- Good for understanding why the game has the properties it does
- Widely available in libraries
Cons
- Connect Four is one example among many
- Not a strategy or competitive-play resource
Practice what you read in the browser at play4row →
Frequently Asked Questions
Is there a definitive book on Connect 4 strategy?
The closest thing is James D. Allen's "The Complete Book of Connect-4: History, Strategy, Puzzles". The foundational technical document is Victor Allis's 1988 master's thesis, which is freely available online. There is no large mass-market canon — Connect Four's small theory canon reflects the fact that the game was solved early.
Where can I read Allis's 1988 thesis?
Free PDFs are available through ResearchGate and Allis's personal academic pages. We keep an offline copy at marketing/research/allis-1988-connect-four-thesis.pdf for our own reference. The thesis is the primary source for every modern Connect Four solver, including the play4row engine.
Are there beginner-friendly Connect 4 books?
Allen's "Complete Book of Connect-4" is the most approachable strategy text. For pure beginners, the in-app /learn glossary on play4row covers the same strategic vocabulary (threats, double threats, odd-even threats, the seven-trap) interactively, with worked examples on a real board.
Should I buy a book or use online resources?
Both. The books give you the historical context and the canonical proofs. The online tools — gamesolver.org, the play4row analyse board, the play4row learn glossary — give you interactive feedback you cannot get from a printed page. They complement each other.
Apply what you read
Books are step one. The play4row platform lets you put the strategic concepts into practice — against ten difficulty levels of AI, in ranked online matches, on daily puzzles, and with full move-by-move review of every game you play.