Polar setupPolar is a game invented by Dieter Stein in 2015-2017.
Here is the inventor's website.

Play Polar interactively

Polar is played on square odd sided boards of the sizes 9×9, 11×11 or 13×13. Both players have a sufficient amount of black and white stones.
Connections are orthogonal only. Stones are placed on empty intersections of the initially empty board.

One of the players takes a black and a white stone and places them on any arbitrary adjacent points. The other player may now decide on which color to play. The diagram shows a setup example.
Polar setup Black starts, then players take turns placing one of their pieces on an empty space according to the following rules. Connected stones form a group and same-colored connected stones within a group are called a section. A group may never consist of more than two sections!

Players may only pass if they have no moves left. They must play in a successive turn if moves are available again. The game ends when both players have to pass.

Groups with one or equally sized sections score zero points. For any other group, the player holding the majority section gets the triangular number of section points:

P(n) = n*(n+1)/2

The player with the higher total score wins. Games can end in a draw. The diagram shows an example of a finished game on a 13×13 board. White holds the majority in 7 groups, Black in 5 groups. White wins by 124 to 101.