Now, I usually hate math, but I had to wonder.
If tarot gives 50% yes answers and 50% no answers, is it always correct 50% of the time?
Yea.
If some situation has 0% chance of happening, tarot will still give true answer 50% of the time and wrong answer 50% of the time.
For example, in theory, tarot yields 50 "yes" answers and 50 "no" answers out of 100 readings.
So if situation has 0% chance of being right and was always "no", the tarot would accurately guess "no" 50% of the time.
What if something only had 1% chance of happening?
Tarot would still have 50% chance of guessing if it will happen or not.
Tarot is magic, really. It is above science.