This has been fixed and will be deployed tommorow or later today.
When we say ‘closest to an edge’ we mean ‘farthest to the left or right’, which is equivalent to ‘distance from the center’. We were calculating this distance from the center, with abs(xPosition - boardCenter).
Our problem is that boardCenter was set to boardsize / 2. Our board is 28 by 28, so this is 14. Our center point should be 13.5, but was shifted half a tile to the right. This means that targeting was preferring targets towards the left when there was a tie.
Edit: This fix should be deployed