Othello opening strategy

There are 71 named openings, and you can play strong Othello without knowing a single one. What follows is the part that actually decides games.

The opening is not about owning discs

New players assume the opening works the way it looks: flip a lot, own a lot, win. Othello does not work like that. A single move late in the game can flip twenty discs back, so the count at move ten predicts almost nothing.

Here is a real catalogued opening, the Maruoka, after ten moves. Black has five discs. White has nine. Black is doing fine.

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Black's discs sit in a tight clump in the middle. White's are spread wider, which means more white discs touch empty squares, which means Black has more places to play. That is the trade the opening is really about.

Move one is not a decision

Black has four legal first moves: d3, c4, f5 and e6. They are the same move seen from four angles, because the starting position is unchanged by a half turn and by a flip across either long diagonal. The half turn sends d3 to e6 and c4 to f5; the flip across a1 to h8 sends d3 to c4 and e6 to f5.

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Play whichever you like. Tournament records are all rewritten to start at f5, which is why every named opening begins there. More on the first move.

White's reply is the first real choice

After 1. f5, White has exactly three legal moves, and that choice sets the character of the whole game. Each reply builds a line of three white discs, and the three opening families are named for how that line sits next to Black's row on rank 5.

• 1... f6 makes a diagonal line and starts the diagonal openings. Sharper, more edge play.
• 1... d6 makes a vertical line and starts the perpendicular openings. Calmer, more central, the biggest family.
• 1... f4 makes a line alongside Black's and starts the parallel openings. Strong players avoid it.

Six rules that carry the first fifteen moves

1. Take the smallest flip that keeps your shape

A move that flips one disc is usually better than a move that flips six. Every disc you flip becomes a disc of yours on the edge of your group, touching empty squares, and each of those empty squares is somewhere your opponent can play. Players call the small ones quiet moves.

2. Watch your frontier, not your total

A frontier disc is one that touches at least one empty square. An interior disc is completely surrounded. Interior discs are safe from being used against you; frontier discs are the ones handing your opponent options. A small frontier is the real opening goal, and it is what "fewer discs is better" actually means.

3. Count legal moves

Before you commit, look at how many squares you can play next turn and how many your opponent can. That number is called mobility. If you have ten choices and they have two, you are steering the game and they are surviving it. Running a strong opponent down to one legal move is often the whole plan.

4. Stay off the edges

Edge discs feel safe because they can only be flipped along one line. They are not safe until the edge is finished, and an edge that is one disc short is the standard way to lose a corner. There is almost never a reason to touch row 1, row 8, the a file or the h file in the first fifteen moves. Edge play in full.

5. Never play an X-square early

b2, g2, b7 and g7 sit diagonally next to the corners. Play one while the corner beside it is empty and you are usually handing the corner over within a few moves. The C-squares, the two squares along the edge from each corner, are nearly as bad. Why these squares hurt.

6. Do not chase the corner too early

Corners win games, but you cannot take one that is not on offer, and moves played to set up a corner ten turns away usually cost you position now. Play good moves and the corners arrive. Corner strategy.

How far does published theory actually go?

Further than most people expect. The longest sequence in the catalogue used on this site is the Mainline Tiger, 18 moves deep, and it is still roughly level when it runs out.

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Notice what has not happened. Neither player has taken a corner. Neither has committed to an edge. Eighteen moves of the best-studied line in the game and the position is still all about the middle. That is the clearest evidence for the rules above.

Beyond the catalogue, computers have gone further still. The 2023 proof that Othello is a draw with perfect play published a sample perfect game, and its first eight moves are f5 d6 c3 d3 c4 f4 f6 f3, which the catalogue names COMP'OTH. A perpendicular opening, played quietly, with no early edge contact. What solved means.

The three opening mistakes that cost beginners games

1. Taking the biggest flip every turn. It builds a wide, loose group and hands over squares. Play the small move.
2. Reaching an edge to "claim" it. An unfinished edge is a liability, not a wall.
3. Panicking at a bad disc count. Being down 5 to 9 at move ten is normal and often good. More mistakes.

How to study an opening properly

Reading a move list teaches you very little. Playing it teaches you a lot. Every opening on this site is written as a plain run of squares, like f5d6c3d3c4, which is exactly the format the board reads and writes.

1. Pick an opening from the index and copy its moves.
2. Open the board and paste them into the move list.
3. Play on from there against the computer, twice, once as each colour.
4. Undo back to the branch point and try the other move. Undo is free and unlimited.

Two or three openings played twenty times each will do more for you than seventy names read once. If you want the labels as well, the openings index has all of them, and the notation page explains how to read a game record.