It’s not just the moisture on top of the skin that affects crispiness, though. Fat under the skin also needs an escape route.
If juices and rendered fat accumulate beneath the skin and have nowhere to go, they will turn that once-dry skin wet and flabby wherever it collects.
Separating the skin from the bird, using a metal skewer to poke numerous holes in the skin over the fat deposits of each breast half and thigh, and cutting a few incisions in the skin along the back of the bird all provide ample escape options for the rendered fat.
Placing a sheet of hole punched aluminum foil under the chicken shields all that rendered fat from direct oven heat and prevents it from burning and smoking in the pan.