Othello Openings for Beginners: The First Moves, Tested

The first few Othello openings come down to one choice. Black's four first moves are the same move turned or mirrored, so the real decision is White's reply: the perpendicular, the diagonal or the parallel. In thousands of games between Poozee's computer players, none of the three was a trap, so beginners don't need to memorize lines. What helps is a habit: play quiet moves into the middle and stay off the squares next to an empty corner.

New to the game? Read how to play Othello first. This guide picks up where our Othello strategy guide leaves off and looks only at the first ten moves. Every number below comes from the engine behind Poozee's Reversi, searching a fixed number of moves deep with seeded randomness, so each one can be repeated exactly.

Black's first move doesn't matter

Black moves first and has four choices: d3, c4, f5 and e6. Each flips one disc, and the four positions they lead to are copies of each other, turned or mirrored. We checked that in code by turning and mirroring every position eight ways and keeping only one copy of each.

The same trick shows how few openings there really are:

So after White's reply there are only 3 openings to know. The British Othello Federation guide quoted below recommends always playing your first move in the same place, so that what follows looks familiar. We use f5 in this guide.

Pro tip: Pick one first move and stick with it. Every opening you learn from f5 then shows up on your board the same way round.

White's three replies

After 1. f5, Black has discs on d5, e4, e5 and f5, and White has just d4. White can play d6, f6 or f4, and each flips exactly one disc. The replies are named by the line that flip runs along, compared with Black's first flip (f5 flipped e5 along row 5):

• Perpendicular (d6): flips d5 up the d column, across Black's line.
• Diagonal (f6): flips e5 along the diagonal from d4.
• Parallel (f4): flips e4 along row 4, the same way Black's flip ran.

These names come from the British Othello Federation's introduction to openings, adapted from a book by Brian Rose. It says the perpendicular and diagonal are common in expert play, while "the parallel is considered to be inferior."

Here's how the three compare in our tests:

Rank is the engine's ranking for White, searching 10 moves deep. The Medium and Hard columns are White's score in 4,000 games per reply between two Medium players and 400 between two Hard players. A draw counts as half a win, so 50% means an even game.

The engine's search agrees. Searching every reply 3 to 10 moves deep, it rated the perpendicular best for White at every depth, and from 7 moves deep on it rated the parallel worst.

In games, the gap was small. With two Medium players, White's score moved by 3.4 points between the best reply and the worst. Against itself, Hard plays the same game, or nearly, every time from the same position (more on that below), so for the Hard games we let Medium play moves 3 to 8 for both sides and Hard took over from there. That sample ranked the parallel best for White. When the order changes from one level to the next like this, the reply isn't what decides the game.

The third move: play quietly into the middle

The reply matters less than what Black does next. For each opening, we had the engine score every third move 10 moves deep, and checked the result at 4, 6 and 8 moves deep too.

The perpendicular (f5 d6)

Black has five moves, c3 to c7, and each flips one disc. This is the one opening without a clear favorite: c3, c4 and c5 are close, and which one the engine liked best changed with the depth. The clear loser is c7, the move that reaches out toward the edge. After c3, the engine's choice for White is d3.

The diagonal (f5 f6)

Black has four moves. e6 slips in between White's discs, touches the most discs of any of them, and leaves White only 2 moves. The engine chose it at every depth we tried. White's best answers are then f4 and d6, which are mirror images of each other.

The parallel (f5 f4)

Black has five moves along row 3. e3 flips one disc in the middle, and the engine chose it at every depth. d3 and f3 flip two discs and come next. c3 and g3, out to the side, ranked last 10 moves deep. The engine's answer for White after e3 is f6.

A rule you can use: fewest empty squares around

Across all three openings, the moves the engine liked were the ones tucked in among other discs. To test that as a rule, we took the positions before moves 3 to 10 of 150 games between two Medium players, 1,196 positions with more than one legal move, and scored all 7,199 legal moves with the engine 6 moves deep. Then we counted how often each kind of move was the top choice (or tied for it):

A move with 7 empty squares around it, reaching out into open space, was the top choice only 3.6% of the time. Always playing the legal move with the fewest empty squares around it found the engine's top choice in 45.3% of the positions; a random legal move did it 21.3% of the time.

The number of discs a move flips mattered much less:

Flipping one disc or two made no real difference. Flipping three or more this early was rarely right.

Pro tip: Before each early move, count the empty squares around the square you're about to play. Fewer is quieter. In the perpendicular, that rule picks c5, one of the three close moves.

Opening mistakes: X-squares, C-squares and edges

The worst opening moves are the ones the strategy guide warns about in the midgame. To measure them early, we played 3 to 9 random moves from the start, over and over, and kept the positions where the player to move could make the mistake (so it would be one of moves 4 to 10). From each one we played two games: one after the mistake, one after the best move that is neither on the edge nor an X-square (both picked by the engine 4 moves deep), with the same level playing both sides for the rest of the game.

Each cell is the player's score after the mistake vs after the other move. An early X-square cost about 20 points against Medium and 30 against Hard, and a C-square cost about as much. Other edge squares cost 4.9 points against Medium but 10.0 against Hard: a small cost against a weak opponent, a real one against a strong one.

This is the diagonal opening a few moves on. g7 flips f6 and looks harmless, but it hands White the h8 corner at once: from h8, White flips g7, f6 and e5 back along the diagonal to d4. Searching 8 moves deep, the engine ranks g7 last of Black's nine moves and e3 first.

Practicing openings on Poozee

Poozee's Reversi lets you play Black (you move first) or White against four levels:

• Easy grabs discs with a lot of randomness, and picked each of the three replies about a third of the time.
• Medium looks two moves ahead and varies its play, so it's the best level for trying all three openings. As White it chose the diagonal most often: 45.1% of the time, against 32.6% for the perpendicular and 22.3% for the parallel.
• Hard looks four moves ahead with the full evaluation. In 1,000 test games it answered Black's first move with the perpendicular every time, and in 50 games against itself from the start it played the same game every time, counting turned and mirrored copies as one. If you play the same moves, expect the same answers, which makes Hard a good opponent for practicing one line until you understand it.
• Expert thinks for up to a second a move, and Hint runs the same search for a little less time to suggest a move.

Try each opening from both sides on Medium, then take your favorite to Hard.

Keep playing

• Play Reversi against the computer or a friend
• Othello strategy: corners, mobility and the endgame, tested in thousands of games
• How to play Othello: the rules, passing and scoring
• Othello parity: odd regions and the last move, for the other end of the game
• Checkers openings for beginners, measured the same way
• Chess openings for beginners