Here's something that I haven't heard before.

What on earth is the FILLER board????????????????

If you look down at the boards on the lane, there is board that is much narrower than the rest, the filler board. It is right along the gutter on the left, essentially the narrow 39 board. Stand on it and throw a straight or a hooking ball anywhere between the 15 and 20 board. It should hit. FYI, don't drop your shoulder, unless you are intentionally, trying to clean out the right gutter.