For those who still didn't figure out where the safe spot is.

The worst heroes you can get as opponent are Kerrigan, Raynor and Dia.
If you want to level up murky/aba use the bushes at the bottom to hide.
Note it seems some jerks here reported the method.
After every kill yields 3500 exp. Their AI switches to the higher levels and yours becomes potato.
This method is also very good to level up cho gall FYI.
Pick a cho. Go into the safespot and let a friend go gall and your friend leaves, so the AI deals with the opponents.
This post was edited by Str1k3 on Dec 31 2015 12:54pm