50 grams is too big for a 200 gram snake.
I feed 50 to 80 gram rats to most of my 1000+ gram snakes twice a week, but that's too big imo for a 200 gram snake.
Most of our snakes that size eat 3 week old 25-30 gram rats.
The key is to feed them meals that they don't have to take a week + to digest because then they may not want their next meal, or two, or three ...