Professional poker players hate to be called "professional gamblers" because it's not a valid title for them. Why? - Because for good poker players, poker is not a game of luck. For good poker players, poker is a game of a lot of things, like focus, discipline, intelligence, psychology, math, patience - the list goes on, but one thing is for luck and it is the fact that luck is not one of the words on that list.
Ok, so poker is a little bit of luck at certain moments sometimes, but when you play poker with the intents to make money consistently, than you have to think about the long run. In the long run, the better poker player is always going to win more money. The better of a poker player you are, the less luck there is involved. To be a good poker player, and to decrease the limits of luck, you have to master the skills of psychology and mathematics.
Poker is a game of percentages. Calculating things called pot odds, implied odds, and outs are something that is essential to a winning poker player. When you watch poker on TV you will always notice that the screen always shows the chances that a player has of winning the hand percentage wise. When you play at the casino, and you are in a hand against someone else and they are taking a long time to make a decision and they are talking to themselves, they are usually calculating the odds in there heads. You have to become a human calculator to be a winning player and being able to do so is one of the keys to being successful in the long run - the other one is psychology.
Knowing the math usually gives you the edge on other poker players, but to decrease luck even more you have to master the psychology of poker. You have to be able to make wonderful readings on people and you have to make those readers by carefully evaluated every single move they make. If you just know the math, and you are unable to play the "nitty gritty" of poker then you will be susceptible to being bluffed at a lot and it will result in folding a lot of winning hands. Poker is not just about what cards you get, everyone gets cards at some point - it's how you play those cards. You have to be able to make losing hands win, and you have to be able to call people when you have the best hand. The better you become at doing this the more luck you take out of the game and the more skill you add to it.
There are two reasons people quit their jobs and become full time poker players. One of them is because there are great poker players out there that over luck with great amounts of skill, and the other reason is because there are a lot of people that think just have gambling problems; make sure you are not the latter of the two before you decide to play poker as a part time or full time job and make sure luck is not the main ingredient of your poker game.