Reversi

Reversi is an abstract strategy board game designed for two players. It is played on an 8×8 uncheckered grid. The primary objective is to control as much of the board as possible. Players compete to have the most disks showing their assigned color when the game concludes. This game is valued for its deep strategic complexity despite its simple appearance.

The mechanics of the game rely on the movement and reversal of disks. Players use 64 identical disks that are light on one side and dark on the other. Each player selects one color to use for the entire match. During a turn, a player places one disk on an empty square. To make a valid move, the player must trap one or more opponent disks in a straight line. This line must be bounded by the newly placed disk and another disk of the current player's color. The trapped disks are then flipped, or reversed, to show the current player's color. This process can occur horizontally, vertically, or diagonally. Multiple chains of disks may be captured in a single move.

There are distinct ways to begin a match depending on the specific ruleset used. In the historical version of Reversi, the game starts with an empty board. The first two moves made by each player are placed in the four central squares. These initial moves do not result in any captures. In contrast, the Othello variant uses a fixed initial setup. The game begins with four disks placed in a square in the middle of the grid. Two disks face the light side and two face the dark side. These are arranged so that same-colored disks sit on a diagonal. In Othello, the dark player always makes the first move.

The history of the game involves some mystery and competition. Two Englishmen, Lewis Waterman and John W. Mollett, both claimed to have invented Reversi in 1883. They even accused each other of being a fraud. The game became popular in England during the late 19th century. A reliable mention appeared in The Saturday Review on August 21, 1886. In 1893, the German publisher Ravensburger began producing the game. Some researchers have speculated about even older origins, though no documentation exists to prove it. A 1907 Japanese publication described Reversi using rules very similar to modern Othello.

A major turning point occurred in 1971 when Goro Hasegawa patented Othello in Japan. Hasegawa was a 38-year-old salesman who viewed Othello as an improvement on Reversi. He chose the name as a reference to the Shakespearean play, Othello. The name reflects the drama and conflict between the characters. The green color of the board was inspired by the image of the character Othello leading a battle in a green field. It also alludes to the "green-eyed monster" of jealousy mentioned in the play. This connection is fitting because players "engulf" their opponent's pieces. Othello became a massive commercial success globally. Sales have exceeded $600 million, and over 40 million classic games have been sold in more than 100 countries.

Competitive play involves strict rules and specialized tools. In international tournaments, players often use a standard time control. In the World Championship, this is typically 30 minutes per player. Players may also use transcript sheets to record every move on an 8×8 grid. This helps resolve disputes regarding illegal moves or incorrect flips. An alternative notation uses letters 'a' through 'h' and digits 1 through 8 to label the board. However, these numbers run in the opposite direction of the standard chess notation. To handle complex tournament situations, mathematicians created the Brightwell Quotient. Invented by Graham Brightwell, this is a specific formula used to break ties in the World Othello Championship.

Reversi and Othello connect to various fields and different ways of playing. The game has moved from physical boards to digital screens. Othello was one of Nintendo's first arcade games and was later ported to a home console in 1980.

Beyond standard play, there are unique variants like Anti-Reversi. In this version, the rules for placing disks remain the same, but the goal is reversed. The player who ends the game with the fewest disks of their own color is the winner. Whether played for fun or in professional championships, the game remains a significant part of global gaming culture.