[2020] How does the game which map you play on in ranked?

I have a quick question about how the game decides which map I play on, because some times I play 10 matches and I'll play Border 4 times back to back and there are some days I won't play Border in 10 matches.
Same with Consulate and Bank if I play Consulate I'll play on Bank next.
So is it an algorithm or is it totally random, does my rank or level have anything to do with which maps I play or the number of players that are playing?