How do you win at Reversi?
Most people lose at Reversi because they try to flip as many discs as possible. The players who win do almost the opposite. Here are the principles that actually decide games.
Corners and mobility beat disc count
A disc in a corner can never be flanked, so it becomes a permanent anchor - take corners whenever it is safe. Just as important is mobility: aim to keep plenty of good moves available while starving your opponent of them. Counter-intuitively, holding fewer discs in the middlegame is often winning, because it means your opponent has over-committed to squares you can flip later.
Avoid the danger squares and count parity
Never play the X-square next to an empty corner - it usually hands that corner to your opponent. In the endgame, count parity: arrange to make the final move in each empty pocket, because the last disc into a region tends to flip the most. Put these together and you will win far more often, whether on the free-opening board or in Othello.
Related questions
Why are corners so important in Reversi?
Corners are the most valuable squares in Reversi because a disc placed in a corner can never be flanked or flipped. It becomes a permanent anchor that lets you flip long lines for the rest of the game and stabilise entire edges. Most Reversi games are decided by who wins the corners.
What is mobility in Reversi?
Mobility is the number of good legal moves available to you. Strong Reversi play keeps your own mobility high while squeezing your opponent's down, so that eventually they are forced into bad moves - like giving up a corner. Mobility usually matters far more than how many discs you currently own.
Why do I keep losing at Reversi?
The most common reason players lose at Reversi is chasing disc count - building a big early lead that collapses when the opponent takes a corner and flips it back. The other frequent culprits are playing the dangerous squares next to empty corners and running out of good moves. Fix those three habits and your results jump.