Othello / Reversi: The Black-and-White Game黑白棋：Othello / Reversi
One of my favorite board games我最喜欢的棋类游戏之一8x8 / Strategy / AI solvedOpenings / midgame / parity开局 / 中盘 / 奇偶性
Play Othello在线下一盘黑白棋
Play against a stronger built-in AI by default, or switch to local two-player mode. Legal move hints, automatic passes, undo, and endgame scoring are included.默认与内置增强 AI 对战，也可切换为本地双人模式。包含合法落子提示、自动跳过、撤销和终局计分。
Gold dots mark legal moves. The AI searches ahead with corner, mobility, stability, and endgame heuristics.金色小点表示合法落子。AI 会结合角位、行动力、稳定性和终盘局势进行搜索。
Why This Game Stays With Me
Othello, also known by the older generic name Reversi, is one of my favorite board games because it has an unusually clean surface and a very sharp interior. The board is only 8x8, every move places one disc, and the pieces simply flip. Yet that simplicity hides tempo, parity, mobility, edge discipline, sacrifice, and a brutal endgame arithmetic.
It is a game that teaches restraint. Beginners chase many discs early; stronger players often prefer fewer discs, more mobility, stable corners, and positions that force the opponent to open the board at the wrong time.
Brief History
Reversi Roots
Reversi-style games appeared in the late nineteenth century in Britain. The core idea was already elegant: place discs and reverse captured lines.
Othello Brand
The modern Othello rule set and brand were popularized in Japan in the 1970s by Goro Hasegawa. The Shakespearean name captures the black-white reversal drama.
Global Spread
Othello spread through Japan, Europe, North America, and Asia as a compact tournament game: easy to teach, hard to master, and perfect for computer analysis.
Rules in One Page
Board and Start
Use an 8x8 board. Four discs begin in the center with two black and two white placed diagonally.
Legal Move
A move must place a disc so that at least one straight line of opponent discs is bracketed by the new disc and another friendly disc.
Flip
All bracketed opponent discs flip to the player's color in horizontal, vertical, or diagonal lines.
Pass and Finish
If a player has no legal move, they pass. The game ends when neither player can move, usually when the board is full.
Win Condition
The player with more discs of their color at the end wins. Draws are possible.
Strategic Memory
Corners are stable, X-squares near empty corners are dangerous, mobility is often worth more than early material, and parity dominates the endgame.
International Competition
The World Othello Championship has been the central international event since the 1970s, with individual and team titles and a strong tradition of Japanese excellence. National federations and online platforms also run qualifiers, rated events, youth competitions, and rapid formats.
Tournament Othello is much less casual than the toy-store rules suggest. Opening books, exact endgame calculation, clock management, and psychological move-order choices all matter.
Has AI Solved Othello?
Yes, in the important modern sense: the standard 8x8 game has been weakly solved by computer search. In 2023, Hiroki Takizawa reported a proof that perfect play from the initial position leads to a draw. This does not mean every position is memorized by humans, and it does not make the game trivial. It means the game-theoretic value of the starting position is known under perfect play.
Mathematically, Othello is a finite, deterministic, perfect-information, zero-sum game. A full strong solution would give the exact optimal move for every legal position. A weak solution proves the outcome from the initial position. The search problem is enormous because early mobility creates many legal continuations, but the endgame can be solved exactly by exhaustive search plus pruning and table techniques.
Game-theoretic value
Perfect black versus perfect white is believed/proved to draw for the standard starting position.
Human meaning
For human play, the game remains alive: mistakes, time pressure, unfamiliar openings, and endgame counting still decide games.
AI meaning
Modern engines turn Othello into a laboratory for search, evaluation, mobility, stability, and exact endgame databases.
为什么我喜欢黑白棋
黑白棋，也常被称作 Reversi，是我最喜欢的棋类游戏之一，因为它表面极其干净，内部却非常锋利。棋盘只有 8x8，每手只下一枚棋子，棋子只是翻面。但这种简单背后藏着节奏、奇偶、行动力、边线纪律、牺牲和残酷的终盘算术。
它很会教人克制。新手常常急着吃很多子；更强的玩家反而愿意暂时少子，换取行动力、稳定角、以及迫使对手在错误时机打开棋盘的局面。
简史
Reversi 源流
类似 Reversi 的游戏在 19 世纪晚期的英国已经出现。核心想法很优雅：落子并翻转被夹住的一线棋子。
Othello 品牌
现代 Othello 规则和品牌在 1970 年代由日本的长谷川五郎推广。莎士比亚式命名强调黑白翻转的戏剧性。
全球传播
黑白棋随后在日本、欧洲、北美和亚洲传播，成为一种紧凑的竞技棋类：容易教学，难以精通，也非常适合计算机分析。
一页规则
棋盘与开局
使用 8x8 棋盘。开局中央四格放两黑两白，颜色斜向相对。
合法落子
落子必须让新棋子和己方另一枚棋子在直线方向上夹住至少一枚对方棋子。
翻转
所有被夹住的对方棋子都会翻成己方颜色，方向可以是横、竖或斜线。
跳过与结束
如果一方没有合法走法，则跳过。双方都无法行动时游戏结束，通常是棋盘下满。
胜负
终局时棋盘上己方颜色更多者获胜，也可能平局。
策略记忆
角是稳定资源，空角旁的 X 位危险，行动力常比早期子数更重要，终盘则被奇偶性支配。
国际比赛
World Othello Championship 自 1970 年代以来就是核心国际赛事，包含个人与团体冠军，也长期有很强的日本传统。各国协会和线上平台还会组织资格赛、等级分赛事、青少年比赛和快棋赛制。
竞技黑白棋远比玩具店规则看起来严肃：开局谱、精确终盘计算、用时管理和心理层面的次序选择都会影响胜负。
黑白棋已经被 AI 解出了吗？
是的，按照现代棋类数学的定义：标准 8x8 黑白棋已经被计算机搜索“弱解”。2023 年，泷泽广树报告了证明：从标准初始局面出发，双方完美下法的结果是平局。人类仍不可能记住所有局面，游戏也没有因此变得无聊。被确定的只是初始局面的博弈论结果。
数学上，黑白棋是有限、确定、完全信息、零和游戏。所谓强解，是给出每一个合法局面的最优走法；弱解则证明从初始局面出发的最优结果。黑白棋搜索空间巨大，因为早中盘行动力带来很多分支；但终盘可以通过穷举搜索、剪枝和表库技术精确解决。
博弈论结果
标准初始局面下，完美黑方对完美白方的结果是平局。
对人类的意义
对人类来说游戏仍然活着：失误、时间压力、陌生开局和终盘读秒仍会决定胜负。
对 AI 的意义
现代引擎让黑白棋成为搜索、评估、行动力、稳定子和精确终盘表库的实验场。