For anyone with drains down the middle from the rooftop when the building collapses - remove the clear plastic guard and plastic combo that the balls land on. Place a small 3/8 or 7/16 post rubber or stack of washers on the right post that plastic mounts to (the one holding the wireform ramp). Then screw down the plastic pieces again being sure to not overtighten. This gives that clear plastic a bit of right to left lean and sends the balls to the left flipper.
I've checked and checked and checked and mine was dead level side to side and all balls flowed right between the flippers. Now they go to the left flipper as intended and you have no unsightly patch on top of the plastic