Just had a ton of fun playing this variant I came up with and thought I'd share. The rules are the same, however, the board is set up differently:

https://lh5.googleusercontent.com/-trSDqPLsgLU/Ts_pc4XqhGI/AAAAAAAAAGg/WpugzLRWdpQ/s800/DiamondBT.jpg

The green pieces are boundaries. The action is off to a quicker start than in 8x8 breakthrough, even though everyone still has 16 pieces.

What is the objective? There is only one backrow location? Do you have to get to that square?

Yep.

Looks like it could be fun, where did you play?

I used the Sandbox feature on iggamecenter.com to try it out. It has a little bit of a different feel to it, as getting only one pawn to break through the main line is usually not enough because of the “goalkeeper” at the end. One pawn must be sacrificed to get the goalie to move out, so that a second can sneak in.

Right. Or be forced to move in Zugzwang.

seems like a good idea to keep the game fresh. The first moves still feel very random to me