Posting: On your turn, select a movie and check to see that it hasn’t been done before. Post a frame from the movie when you pause it at the 20:20 mark. Wait for at least 24 hours, but you can shave 4 or so hours off that if you get a few guesses. Then post a frame from 40:40 and wait again. Continue for 60:60, 80:80, 100:100, etc. If nobody can guess your movie, you lose and must post again.
Guessing: Use only what’s in your mind (don’t Google it). You get one guess per frame, and if you want to guess again, you’ll have to wait until the next frame gets posted. If you guess the movie, it’s your turn to post.