Probability

I have a question what is the probability of hitting a set on the flop??? Because you can win a big pot!!

With a pair in the hole, there are two (2) cards left in the deck that match your pocket pair. Either would make a set on the flop (3 cards), so the probability would be 2X3=6 times on 50 cards left which is 6/50=12%.

Someone said that with a poker pair, there is always a reason to see a flop...

I can't give you exact numbers, but a good rule of thumb is to aim for 1 in 8-9 hands. For example, calling someone's 3-bet with a pair in hopes of hitting a set should only be done if you win at least 8 times as many chips, so as not to mathematically drive yourself into negative expectation. There are, of course, exceptions to this rule, but for the other 95 hands out of 100, you can safely apply the Rule of 8.