AK tuning and other modifications.

A block on the only road means a restart. The limit for the block's location is 112. If you see a unit on the only road, and breaking through it will result in the death of the polar army or more, then it's a block, which means a reason to inform your opponent about a possible restart due to the block (However, you cannot check and attack the unit yourself; you need to send the save to the tournament judge).