How many games per day are people playing to stay at the top rank?

I'm kinda new to the game, been mythic 2 months in a row but can't manage to stay under the 1200 rank to get the play in points.

I usually aim 10 wins until I reach mythic, then aim for 15 wins everyday.

Looks like I'm averaging 25 matches to get the 15 wins, so the positive gain is 5 wins. Which grants me 50~100 rank.

Unfortunately in the next day, I keep losing around 200~300 rank positions so after a week or two I'm already out from the top 1200.

So, how many matches are you guys playing? Or are these people just extremely good so they barely lose, pumping up their positive gain per day?