You may see the order of symbols on each wheel and calculate the odds of winning the same as counting cards.

Well, why is that pesky RNG generating random numbers? When you press play, the program picks the latest "set" of numbers generated. Each number in the "set" is just one of the symbols on the reels. If you have three reels, slots betting you get three numbers within the set. Consequently, when those virtual wheels spin, the RNG has already calculated where the reels are going to stop.

It will be so convenient for you if you can see the result of one spin and after that calculate the odds of the next spin going over the same spinning sequence a given number of rotations to pick the next symbol on the reel.