I prefer the term "spatchcocked" rather than "butterflied". Just sounds better IMHO
I've seen some recipes distinguish between the two words. In one Italian cookbook, for example, the instructions to butterfly
a whole chicken say to split through the breast leaving the backbone intact and then flatten the bird. Spatchcocking
usually implies removing the backbone entirely and then flattening the bird leaving the breast intact. These words can describe two different ways to open up and flatten a chicken, although many folks use the words interchangeably.
At the Hispanic markets called "Pro's Ranch Market" in AZ, I've seen butterflied whole chickens grilling on their Santa Maria style grills with the breast split open and flattened and the backbone still intact. No part of the chicken is missing -- it's just split completely open at the breast and flattened.
The advantage to this method is you get the best of all possible worlds. The chicken is flat, so it grills or roasts more quickly than an upright bird. But you waste nothing
. You don't lose the backbone or the oysters as you do with spatchcocking. I love homemade chicken stock, but I buy a bag of necks for the stockpot rather than throw all my backbones in there.
Here's a link to a recipe with photos showing a whole chicken both before and after cooking with the breast split open and the backbone still intact. Scroll down through the recipe to see all the photos:https://gowstakeout.wordpress.com/tag/roast-chicken/