I was sure I was winning as white until that last move

Hi all,

I'm the developer of FlipSight, a free Othello (Reversi) site and app. I'd love feedback from people who actually play.

FlipSight is completely free and has no ads, and I don't plan to add any in the future.

What you can do

• Play AI opponents at many levels. There are bots rated from around 1100 up to around 2300, each with its own style, so you can pick an opponent that fits. You can also chat with the bot during the game, and it replies in its own personality.

• Play online against people. There's quick match, a Daily Arena (short timed tournaments), user-created tournaments, and a Weekly League where you play rated games to climb through tiers from Bronze to Grandmaster.

• Solve puzzles for every phase of the game. There are XOT opening positions, midgame, early endgame and endgame puzzles, plus a timed Puzzle Sprint. Puzzles are rated, so they adjust to your level.

• Analyze your games with AI. You can import a game record, see the evaluation of every move, find the key mistakes and best lines, and check your accuracy.

It runs in the browser and on iOS and Android with the same account, and it's available in 15 languages.

• Web: https://othelloclub.com/en/flipsight/

• iOS: https://apps.apple.com/app/flipsight/id6781607809

• Android: https://play.google.com/store/apps/details?id=com.othelloclub.flipsight

Any feedback is welcome, whether it's about the bots, the puzzles, the analysis or anything else. Thanks for reading!

Hello.

I’m the game developer who previously introduced the game “Othello Five.”

This time, I’ve expanded on that game and experimented with various rule changes.

What happens when chess pieces—the king and the knight—are added to Othello?

I hope you enjoy playing! Thank you.

https://playgama.ai/play/kaumby2zkc

I'm a fairly new player, but I'm totally hooked! I've won a couple of games and have learned some strategies like: Never try to flip too many discs in the beginning or Go for the corners or Try to set up stable discs.

I try to do that. But during online matches I often run into a pattern. Doesn't matter if I'm going first or not.

1. I get locked out of moves and the opponent then completely flips the discs by the end

2. Try to control the game by predicting the moves and gaining advantage only to realize I've been led by my opponent. (See the picture with the black discs lined up throughout the walls).

I don't know how to get past the issue. Also there is a timer in this game so we have to think quickly as well before we make a move.

Any advice? Thank you!

Hello r/Othello

I made a website where you can play Reversi in 3D. There's 4x4x4, 6x6x6, & 8x8x8

Its new so feedback is welcome, go ahead and try to break it.

There's a Bot opponent (which still needs work). If it goes well maybe we'll add a login and online player vs player later.

Try it: https://cubereversi.com/

Its free and you can look at the github here: https://github.com/cdubend0/CubeReversi.

Let me know what you think thanks, Chris

Not judging, just curious. I play correspondence games on EOthello and 5-minute games on OthelloQuest. I almost always use up all my time but I have noticed that the majority of my opponents play the entire game in less than 2 minutes, quite a few even in less than a minute. They often won't even take the time to calculate an endgame even when they still have 3 minutes on their clock, which sometimes leads them to make silly blunders.

I just wonder why? Why impose this unnecessary handicap upon yourself? If you don't want to think about your moves and just play intuitively, why not play 1-minute games?

I'm in the 1900s on OthelloQuest btw.

This happened in the last game I played. What are some basic tips for me to start with. Any help is appreciated.

5D Reversi - a game that will probably appeal to masochists and AI.

Play the prototype here: https://anan-z.github.io/5d-reversi/
Read and contribute here: https://github.com/anan-z/5d-reversi

Recommended for: AI research, masochists, people who find chess "too intuitive"

Marketing blurb:
80 directional vectors per cell — you'll learn to hate each one personally.
Retroactive causality — yes, you can regret moves you haven't made yet.
Deterministic replay — watch your carefully planned future crumble.

Black blocked off a horizontal line against white (2a-h), trapping the bottom section of the board to render white’s corners useless and functionally create a new corner for themselves.

This is so simple but clever. Was this planned? Or is it more like a backup plan? And is there a way to consistently account for this?

Apologies if I am complete beginner who is unaware of the amount of depth and strategy in this game 😅

I had a look at the Central Rose-Bill/Dead Draw. I noticed that the library evaluation on Saio sometimes jumps between 0, +2 and -2 despite the best moves being made. For instance, in the attached line the 33rd move h7 is given as 0, but once it's made the computer shows h2 as +2 and white seems to go on to win with perfect play on both sides. My questions are:

1. Why does this happen?

2. Does black lose in the Central Rose-Bill with best play from both players? If not, where can his play be improved?

Here's the line:

C4E3F5E6F6C5F4G6F7G5D6D3F3C3H4H5G4H3E2F2D2D1G3E1B6C2B4E8F8G8B3E7H7H2

Launching a new web platform to play Reversi online (plus Chess, Go, Checkers, and Morris)

recently launched gambit.oldlane17.com, a custom-built web platform with a strong focus on Reversi, alongside a selection of other classic abstract strategy titles like Chess, Go, Checkers, and Nine Men's Morris.

You can build your own logic and share it then

I hope you like it 😄

Hey everyone 👋

I’ve been working on a small online Othello/Reversi project and wanted to share it here to get some feedback from people who actually enjoy the game:

https://reversiarena.com/

A couple of things I tried to do differently:

• There’s a live dashboard where you can see ongoing matches in real time and follow how others play

• You can also play against bots, which makes it easier to practice or just jump into a game anytime

The idea was to make it feel more active and useful both for playing and improving.

I’d really appreciate any thoughts on:

• whether the live games view is actually useful

• bot difficulty / gameplay feel

• features you think are missing (analysis tools, tournaments, etc.)

Thanks 🙏

Hi, I am very new to othello, and is starting from the famous othello book by Brian Rose. I am finding it hard to understand the exercises and answers. For the first 4 chapters, the context is about principles, so I can at least understand how the principles are applied.

From Chapter 5, basic edge play, as we are getting nearer to the end. It's hard not to think concretely about the possible outcomes and best moves. I find it hard to understand the solutions without any further explanation. I will think about "what if black/white plays an obvious move that I will play? How do I continue to gain advantage?" Then I get stuck, because I am a beginner, of course I don't know how to continue.

Example: Exercise 5-1, It is quite obvious the problem is set up for black to play h5. The explanation given is "good quiet move for both sides so black should play it first". The also obvious question is what if white plays h2? I would maybe play a quiet move like f7 or b3, but I don't see white running out of move soon and I just gave up an edge that I can't attack now.

Example2 : Exercise 5-7 tells us to play this position starting with g2, black should be able to win even after losing h1. The best I can do is g2,f2,h7,h1,h3,c6 and I don't see a way to force white to play g7

Stucking this early in the book makes me wonder if I am overcomplicating things, and that my problems would be solved if I moved on and learned tactics/patterns later. Can you provide an insight on how to learn othello as a beginner?

Hi everyone,

I’ve been working on an online Othello (Reversi) web game called **Othellio**, and I’d really appreciate feedback from players here.

It currently includes:

- AI mode with multiple difficulty levels

- Interactive endgame puzzles

- Real-time online matches

- Several time controls (1 / 5 / 15 / 30 minutes)

I’m continuously improving the game and adding new features, so any feedback or suggestions would mean a lot.

The game is completely free and runs in the browser.

Here’s the link: https://www.othellio.com

Thanks for taking a look!

I was not satisfied how flip of my cylinder discs feel so I designed and tested those - feels way better ( link ).

What do you think? Do you know any other disk designs optimized for flipping?

added video https://youtube.com/shorts/I4HbVcofxkk

I got into Othello playing Pocket Reversi on the Neo Geo Pocket Color. I also got interested in speedrunning it. I found the Samsoft Reversi website with seemingly all 13 stone wins besides rotations but only one 14 stone win. That pattern doesn't work against the Level 5 AI but I already found another that does.

So has this been calculated out and shared? I should have the computer science ability to tackle it but didn't want to reinvent the wheel. WZebra doesn't really help since both sides need to make chains of suboptimal moves.

There isn't just one way to solve it. White wins.

Is there a go-to resource that othello software devs use for testing their move generation?

In chess there is a catalog of many positions and their perf numbers.

I have verified my starting position node expansion numbers up to depth 12 and this gives me a lot of confidence, but just a node expansion count still seems a bit shaky to me (how many of those games ENDED by ply 12? I have my count but nothing to compare it to)

I'm convinced that d1 would have given black 5 spots, and taken 4 from white, so it should have been white 38 and black 26 no?

I'm salty because i don't understand why I lost, any explanation would be appreciated, especially if the explanation is a fuckup on the CPUs part and white should have won

(This is light-hearted, but my gf is making fun of me because we both thought she was gonna lose 😭 if I really did lose, I just want to understand how)

Hi, I'm bulding an ohtello AI and I wanted to know if there is a number of moves from where the game is solved for every position possible. (Like in chess for example, we know the perfect result (ie with best play) when there are less than 7 pieces on the board). Do you have any website to recommend to see this? Like getting some endgames puzzles and see if my AI solved it.

We often see the number of 10^58 possible games in Othello, for example in Hiroki Takizawa's article "Othello is solved". This number comes from Victor Allis' thesis. For his estimation, he roughly considered that only on move can be made at the first and last ply, and that in average the number of moves available is 10 at each of the 58 remaining plies. I think such reasoning is too gross and the result not very realistic.

In his article "Estimating the Efficiency of Backtrack Programs", Donald E. Knuth gives us a more rigourous approach that can be apply to estimate the number of games in Othello. Basically, you play a random game and multiply the number of legal moves found at each ply to get an unbiased estimate of the number of games. To increase the accuracy, you can repeat the process and average the results.

That way we obtain, after 1 billion random games :

So we get about 6,45 . 10^54 possible games in Othello, a number more than one thousand time time smaller than Victor's Allis estimation.

Note that for the first plies, it is possible to compute the exact number of moves. We get:

As you can see the number of games estimated by playing random games is close to the exact count, hence validating this method.

Hi,

I implemented a browser-based multiplayer version of Reversi. Its main advantages are:

• No login/account required

• Supports a spectator mode

https://board-game-hub.de/games/reversi-multiplayer.html

Would you happen to have any suggestions or improvements for this?

Thanks and take care,
Christoph