Opening family
The parallel opening
The short answer
The parallel opening begins 1. f5 f4. White's reply leaves three white discs on d4, e4 and f4, a row running alongside Black's row on rank 5. It is White's third and least respected answer, and it is the only opening family with no catalogued continuations at all.
Why it is called parallel
Black's first move flips e5 and builds a row of three black discs across rank 5. White's three legal answers each build a row of three white discs of their own, and the family names describe how the two rows sit together.
Here White plays f4, which flips e4 and lines up d4, e4 and f4. That row runs in the same direction as Black's, one rank above it. Two lines running the same way and never meeting are parallel, so this is the parallel opening. The other two answers give a diagonal line and a perpendicular one.
The smallest family in the book
The catalogue this site uses holds 1 parallel opening,
31 diagonal ones and 39 perpendicular ones. The single parallel entry is
the opening itself, f5 f4, with nothing after it.
That gap is not an oversight. Opening names in Othello are given to lines that people actually play often enough to argue about, and the parallel is avoided at every serious level. No games means no analysis, no analysis means no names.
What is wrong with it
Look at the diagram again. White's three discs and Black's three discs form two flat rows facing each other across the middle of the board. Every one of White's discs is on the frontier, meaning it touches an empty square, and a frontier disc is a square you are offering your opponent.
Black then plays anywhere on rank 3, flipping through the white row and taking the middle back. Whatever White does next, White's discs stay spread out along a line while Black's stay bunched near the centre. Spread discs and a big frontier are exactly the two things that cost you mobility later, and running low on legal moves is how most Othello games are lost.
Compare that with the perpendicular, where White's column and Black's row interlock rather than face off, or the diagonal, where White's line cuts through Black's. In both of those, White's discs sit at an angle to Black's and neither side gets a clean shot at the whole group.
Is it losing?
Nobody has published a proof either way. Othello as a whole was weakly solved in 2023, and perfect play from the starting position ends in a draw, but that result is about the game from move zero. It does not say what the value of 1. f5 f4 on its own is, and this site is not going to invent a number for it. What "solved" means here.
The honest summary is the one strong players give: the parallel is playable and it is worse. Treat it the way you would treat a slightly passive opening in any other game. You are not lost, you just have less to work with.
Playing against the parallel
You will meet 1. f5 f4 mostly from casual opponents and from weaker computer levels. There is no line to memorise, so use the general rules:
- Keep your discs central. Flipping a lot of discs on the edges early leaves you fewer safe moves later. The mistakes to avoid.
- Count your moves, not your discs. Having more legal options than your opponent matters far more than having more discs on the board at move ten.
- Leave the squares next to the corners alone. Nothing about this opening changes the fact that an early X-square usually loses a corner. X-squares and C-squares.
- Do not chase the win. A slightly better opening is worth very little. The game is still decided in the last twenty moves.
Playing the parallel as White
If you want to play it anyway, and there are reasons to, play it knowingly. It takes your opponent straight out of book, which is worth something against someone who has memorised Tiger and Rose lines and nothing else. Be ready to spend the next ten moves working for it rather than recalling it.
If you would rather stay on solid ground, the two other replies to f5 are both fine, and each has a page here with its own diagrams and its full list of named lines.
Every named parallel opening
The whole family, listed the same way as the other two for consistency.
| Opening | Also called | Moves |
|---|---|---|
| Parallel Opening |
f5 f4
|
Keep reading
- All Othello openings, the full index and how the families work.
- Diagonal openings, White answers f5 with f6.
- Perpendicular openings, White answers f5 with d6.
- Opening strategy, what to aim for when there is no book line.
- Try it on the board, paste
f5f4into the move list and play on.
Frequently asked questions
What is the parallel opening in Othello?
It is the line that starts 1. f5 f4. White's reply leaves three white discs on d4, e4 and f4, a row that runs alongside Black's row on rank 5. The two colours end up in two flat lines facing each other.
Why does the parallel family have only one named opening?
Because almost nobody plays it. Strong players treat 1... f4 as White's weakest answer, so no body of studied continuations grew up around it. The catalogue holds 1 parallel entry against 31 diagonal and 39 perpendicular ones.
Is the parallel opening actually losing for White?
Nobody has published a proof that it loses. It is considered clearly worse than the other two answers because it splits White's discs and lets Black keep the centre, which is a practical judgement rather than a solved result.
How should Black answer the parallel opening?
Black has five legal replies, all on rank 3: c3, d3, e3, f3 and g3. There is no book line to follow, so play on general principles. Keep your discs near the centre, keep your move count high and leave the edges alone.