Reversi Board Game

Openings

Othello openings, grouped by family

The short answer

An Othello opening is the first handful of moves, and most of the common sequences have names. This page lists 71 of them, sorted into three families by White's first reply: diagonal, perpendicular and parallel. Every catalogued sequence begins with Black playing f5.

The list below is not typed out by hand. It is read straight from the opening catalogue that the board on this site uses to name your game as you play, so a name here and a name on the board can never disagree.

Black has four first moves and they are all the same move

From the standard setup, Black can play in exactly four places: d3, c4, f5 and e6. They are marked below.

The starting position. Black's four legal first moves are marked: d3, c4, f5 and e6.

Those four squares are the same square looked at from four angles. The opening position is unchanged by exactly three things: turning the board a half turn, flipping it across the a1 to h8 diagonal, and flipping it across the a8 to h1 diagonal. A quarter turn does not work, because it swaps the two colours over.

Follow the squares through those three moves and the four first moves fall into a single group. 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. So whichever of the four Black picks, the position after move one is the same position, seen a different way up.

That is why nobody argues about the best first move. There is no best first move, because there is really only one first move. More on that here.

After 1. f5. Black now owns d5, e5 and f5, a row of three across rank 5. White has one disc left, on d4.

Why every named opening starts with f5

Because the four first moves sit in one group, a game that opens d3, c4 or e6 carries no information a game opening f5 does not. Tournament databases take advantage of that and rewrite every game so it starts at f5, which means one catalogue covers all four starts. Gatliff's published catalogue, the source for the list below, lists each opening under all four roots and this site keeps the f5 branch.

White's reply names the family

After 1. f5 White has exactly three legal moves, and each one produces a straight line of three white discs. The family names describe how that white line sits next to Black's line on rank 5.

Diagonal: 1. f5 f6. White's discs run d4, e5, f6, a diagonal line across Black's row.
Perpendicular: 1. f5 d6. White's discs run d4, d5, d6, straight down the d file, at right angles to Black's row.
Parallel: 1. f5 f4. White's discs run d4, e4, f4 along rank 4, side by side with Black's row on rank 5.

The three families are not equally popular. Diagonal and perpendicular are both taken seriously and both have decades of published analysis. Parallel is regarded as White's weakest answer, because it leaves the two colours in two flat rows and hands Black the easier game, and that shows up in the catalogue: it has one entry and no continuations at all.

Family Opening moves White's line Named openings
Diagonal 1. f5 f6 d4, e5 and f6, a diagonal line 31
Perpendicular 1. f5 d6 d4, d5 and d6, a vertical line 39
Parallel 1. f5 f4 d4, e4 and f4, a horizontal line 1

How to read the catalogue

Each entry gives a name and the moves that produce it, written as a run of squares in a1 to h8 notation. Black plays first and the two players alternate, so odd-numbered moves are Black's and even-numbered moves are White's. If you are new to the coordinates, the notation page explains them in a minute.

Three things are worth knowing before you scroll.

  • Openings nest inside each other. Tiger is f5 d6 c3 d3 c4, and Mainline Tiger carries the same five moves on for thirteen more. The longest match wins, so a game deep in the Mainline is not also reported as a Tiger.
  • Some openings have two move orders. The catalogue holds 99 sequences for 71 names. The extras are mirror-image routes to the same position, and both are real transcripts you might play. Where an opening has two, both are listed.
  • Some openings have more than one name. Older books and national federations named the same lines differently. Alternative names are shown as aliases, so searching for Bat, Cambridge or Cow Bat all lead to the same place.

Every named opening

71 openings, grouped by family and listed alphabetically. Move sequences come from the catalogue used by the board.

Diagonal openings (31)

Starts 1. f5 f6. Sharp and popular. Most of the well-known animal names sit here.

Perpendicular openings (39)

Starts 1. f5 d6. The biggest family, and the one with the deepest published theory.

Parallel openings (1)

Starts 1. f5 f4. The reply almost nobody plays, which is why it has almost no theory.

How much opening theory do you actually need?

Less than the length of that list suggests. A named opening is a label for a position, not a plan, and knowing that you are in a Rose-Birdie does not tell you what to do next. Below tournament level, games are decided by corners, by how many legal moves each side has, and by who is forced to move first into a bad square. All three are covered on the strategy guide.

Names earn their keep in two places. They let you read game commentary and recorded matches without getting lost, and they give you a way to study one shape at a time instead of the whole game at once. If you want the ideas behind the first ten moves rather than the labels, the opening strategy page is the one to read.

Where to go next

Frequently asked questions

How many named Othello openings are there?

This site lists 71 named openings, taken from Robert Gatliff's catalogue. They are stored as 99 move sequences, because several openings can be reached through two mirror-image move orders and both orders are real games.

Why does every named opening start with f5?

The four legal first moves are the same move seen from four angles, so tournament records are all rewritten to start at f5. The catalogue follows that convention, which is why you will not see an opening whose first move is d3, c4 or e6.

What decides whether an opening is diagonal, perpendicular or parallel?

White's reply to f5. White has exactly three legal answers. f6 makes a diagonal line of white discs, d6 makes a vertical line, and f4 makes a horizontal line that runs alongside Black's. Those three shapes give the three families their names.

Do I need to memorise openings to play well?

No. Corners, mobility and stable discs decide far more games than opening knowledge does. Learning names is useful mainly so you can read commentary and look up games. Start with strategy instead.

Why does the board not name my opening?

Two reasons. Either you did not open with f5, in which case the detector has nothing to match, or your moves have left the catalogue. Both are normal. Play on; leaving book is not a mistake.

What is an alias in the list below?

A second published name for the same sequence. "Bat" and "Cambridge" both refer to the opening this catalogue files as Cow Bat, so the alias is shown next to the main name and you can search for either.