Have a look at the position values in the normal 6圆 game: There are only a few exact solutions (main lines) of the normal game resulting finally in +4 for white, but just have a look at the third move of the reversed game: after C2 B4 there are already 3 possible moves of black (C5, D5, E5) which are all best moves and lead to +2 for black in the end. You will find another example of this on the pages with the exact solution of the normal and anti 6圆 games. This affects the search algorithm since there are more moves with closer values to the best move, and therefore the pruning needs more calculation. On the left picture in the normal othello, the range of the possible moves’ values is, while on the right in case of the reversed othello the range is. Both are the “same” board positions, but the first is a normal othello and the second is a reversed othello. To clarify this have a look at the following two pictures. Interestingly from my experience a reversed game position is more difficult to solve perfectly than the same position in the normal game mode. This is one of the reasons why I really like reversed games (you are not wiped-out psychically ). Of course one can lose by -64 if he really wants to, but with a very minimal strategy this doesn’t happen. Even a beginner human player can force the opponent to have at least 5-10 discs at the end, thus the average final wipe-out result (disc difference) is between -32 and -44. A beginner will definitely lose, but only extremely rarely will the final difference be -64. In the case of reversed games the situation is more difficult. So in a normal game the most probable outcome is the draw, but -64 and +64 results appear very often in comparison to the reversed games. Of course the better the players are, the closer the final result will be to a draw. Thus from the normal endgame result’s point of view all results from -64 to 64 are very probabilistic. The program will flip all your pieces, you will not even be able to play each time you want to, because you will probably have to pass many times. If you are a beginner in reversi games you can be easily defeated by a program 64:0. The only source I have found on the web about the reversed Othello games is a high level description of Turingtest ( ), who played several games in the MSN gaming zone’s tournaments. My personal opinion is that the reversi game - and especially the normal game type - is not really convenient for human players.Īnd now after a philosophical aside, let’s come back to the reversed reversi game.

How many human players will risk this move without knowing the exact outcome? Computer programs calculate and make these moves without any fear. Just think of the situation when an x-square has to be played because this is the best move. But as soon as the game stage reaches an unknown position intuition becomes ineffective and brute calculation wins.

Opening strategies calculated by top programs are a good starting point and help human players too.

I prefer the help files of the WZebra program created by Gunnar Andersson (see the links), but other pages are also very useful. If you are really interested there are many sources available on the internet. I will skip to explain in detail how one can learn to play Othello (reversi) games. The most evident is not to move into the X- squares (B2, G2, G7, B7) if you don’t have to. In a normal game there are several hidden traps you can encounter. If you follow a game played by a top program you will see that the right strategy in a normal game is to find the equilibrium of the number of own and opponent’s pieces: if you have too many pieces, it can easily happen that you lose mobility and finally the game. Anti mode = Reversed mode: the winner is the player who at the end has the least number of discs.

Normal mode: the winner is the player who at the end has the most of discs.

Othello = Reversi: (means the same game type).

All rights for those who are not familiar with what the reversed or anti othello means:

Othello strategy