Last updated : July, 2006.

All rights reserved.

@F.Pittner

mail@tothello.com

Solving the 6x6 reversed othello

As far as I know Tothello was the first program in the world which calculated the exact outcome of the 6x6 reversed Othello game. Since the program uses sophisticated search mechanisms it takes only a few minutes to calculate the exact final result of the game.  What this achievement made possible was that from the very beginning Tothello had been designed in order to play on 4x4, 5x5, 6x6, 7x7 and 8x8 size boards. And because nowadays top othello programs solve in a few minutes game positions with 32-36 empties, this achievement (solving the 6x6 anti game) is not a big surprise.

In this game black wins with at least 2 pieces. To be sure there is not only one perfect solution, since the game space contains lots of solutions with the same result. For instance at the second move, white can choose either C2B4 or C2D2. Both will lead to a result of minimum +2 for the black player.

Two perfect solutions, for example:

C2B4D5E2E3C1B1E4D1D2F2E1F3F4B3D6A5A4A3A2B5B2E6C5C6F1F5E5F6B6A6A1

C2D2E4D5E3F3F4F5E1B3B2E5C5B4A4D6A5B1D1C1E2A2B5A3C6B6E6F2F1F6A1A6

In both cases the corners are occupied in the very last stage of the game. In the pictures below you will find two perfect solutions of the game.

Solution no 1:

a6_01

a6_02

a6_03

a6_04

a6_05

a6_06

a6_07

a6_08

a6_09

a6_10

a6_11

a6_12

a6_13

a6_14

a6_15

a6_16

a6_17

a6_18

a6_19

a6_20

a6_21

a6_22

a6_23

a6_24

a6_25

a6_26

a6_27

a6_28

a6_29

a6_30

a6_31

a6_32

Solution no 2:

a6_01

a6_ii_01

a6_ii_02

a6_ii_03

a6_ii_04

a6_ii_05

a6_ii_06

a6_ii_07

a6_ii_08

a6_ii_09

a6_ii_10

a6_ii_11

a6_ii_12

a6_ii_13

a6_ii_14

a6_ii_15

a6_ii_16

a6_ii_17

a6_ii_18

a6_ii_19

a6_ii_20

a6_ii_21

a6_ii_22

a6_ii_23

a6_ii_24

a6_ii_25

a6_ii_26

a6_ii_27

a6_ii_28

a6_ii_29

a6_ii_30

a6_ii_31

How to calculate perfect outcome of the 6x6 reversed reversi game with Tothello?

First you need to switch off its book usage. Set the midgame search depth to a value greater than 22, set the time limit type to “no limit”, and enable the background calculation. Make the first move and follow the results.

[Tothello home page] [Reversed othello games] [Guideline of reversed othello] [Solving the 6x6 normal] [Solving the 6x6 reversed] [Perfect solution 1 (6x6 reversed)] [Perfect solution 2 (6x6 reversed)] [Tothello: learn to play] [How Tothello thinks] [Some theory] [Difficult game positions] [Download] [Useful links] [Awards, other links]