Some example situation of real challenges? May be one or two from the experience?
To make it short: You don't know your opponents hand. So, while you know, you have maybe two pairs, it's hard to tell, how strong your hand is, without knowing against what hand you are playing. Only when you have the nuts (=best possible hand), you can be 100% sure to win the pot. And this goes only for when flop, turn and river have been dealt. Pre-flop AA is the best hand, but you can still lose the hand, even against some weak hand like 72.
Every hand is unique and presents a new challenge.
This hand is pretty strong, you have a full house. You might want to risk all your chips here:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fabload.de%2Fimg%2Fhand1zckj4.jpg&t=665&c=4YLYvre188HDFg)
But look, what your opponent has:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fabload.de%2Fimg%2Fhand2ptj76.jpg&t=665&c=nNWQXQmIamxGxw)
And even your opponent can't be 100% sure of winning that hand, because there could be a third player in the hand:
(All screenshots taken from: https://www.cardplayer.com/poker-tools/odds-calculator/texas-holdem)You will always have some uncertainty, unless in those rare cases, where you have the nuts for a certain board. You can play around a bit with that odds calculator and create some scenarios to learn about probabilites.
How much bitcoin I will need for this?
The entry fee is 0.001 Bitcoin.