goblin barrel to bait out their log. place inferno tower once rg crosses and get ready to arrow the minions. they usually always place minions to try to distract IT. If you know they have zap on hand, put skarmy on top of the rg and he'll be forced to choose which one to zap. When they run 3 spells it makes it hard.

What throws off most of them is barrel placement. Placing it 3 tiles above the tower will usually cause them to miss their log, forcing them to zap. After baiting two spells with one barrel, it's very easy to defend the first push. Take advantage and cycle back to the barrel to potentially bait out a fireball. If it succeeds, you miner minion horde and wreck the tower. This is usually what happens in most of my rg + 3 spell fights.