Hi Darkquest,
I'm no expert in programming, but there are different means to do this.
I assume they let the bots play against each other with the same card combinations very often in a very short time (processing) and see which moves are most likely to win you the game.
It is no bot, it is an AI, means an artificial intelligence!
Plays not too strong, but yes thinks like a human lol...
What a nightmare lol...he must be so sad about his life, really!
Let's give him all the love he needs!
XOXO Archy