They do this a lot in pre-production, usually not for the entire movie though. Mostly for action scene framing and choreography, its called Pre-VisIs it common for films to have "rehearsal movies" likes this? I honestly can't think of another film you could watch like this, at least not in its entirety, shot for shot.
Sweet, the guy in the getting hit in the knee then hit with Ray's butt at the end is a friend of mine and my brother. He did a lot of the fight coordination, and was also Macchio's stunt double (at least for the fight with Johnny scene)Finally got around to binging season 2...so good. Sting Ray is the real mvp.
He got my brother a small part in one ep, but they decided he looked too "mature" compared to the other kids. So they replaced him in another scene with someone who doesn't really look like him. haha. Guess it didn't matter cause he didn't have any lines.
My bro (asian guy on the left):
Not my bro: