Irregular 3-player map for creative and sneaky fighting styles, lots of common areas to clash over the ore, and lots of areas that can be hard to defend, with several attack vectors to each base. The left player has the least ore security, and will likely end up having too many vicious battles at the middle patch to reliably harvest there, though gets a bit more ore at the top corner if they can defend their harvesters that far away.
http://aproposer.net/ra2/chasing.zip