Starting Hands. Part 2

Hands with sequences

Example of hand with medium sequence: 9 ♠ 8 ♠ 7♣ 6♦.

Example of hand with top sequence: A ♣ K ♥ J ♣ T ♠.

Example of hand with youngest sequence: 6 ♦ 5 ♣ 4 ♠ 3♣.

Hands with sequences are very important in pot-limit Omaha.

If the sequence is young, such as 6-5-4-3, its suit will have value only when you play one on one. If you have several opponents who make raise and re-raise, then in such situations one of the opponents will have higher flush draw.

Sequence is a great "straddling" hand. If you have studied your opponents, and you know that one of them makes a raise on the aces, and the second calls on high suited connectors. Now they are both in play, and you're holding something like a 7-6-5-4. You think: "If on the flop come young or medium cards, then pot will be mine. So you can safely continue to play such hand. Although, if you have one opponent, you should not play with such cards. Playing one on one, you will not call a large raise, having such hand.

Suppose you have made two pairs on the flop and you know that your opponent plays with aces. You are a favorite. But as soon as on the flop came a pair (any pair, not yours), you will automatically lose. With these cards it is very dangerous to play.

Another category of playing hands with sequences is three cards and a pair (8-8-7-6, 7-7-6-5, 9-8-7-7, and so on).

If you know that you are playing against a top pair, and you made medium pair on the flop in addition to your straight draw, then at this point you are a favorite. If on flop comes your eight, it is likely that it will not be associated with high pairs of opponents, so that they can not make a straight (unless some back-door straight). So, almost any three-card sequence in combination with a pair may be very good playing hand. 

I said "almost", you should forget such combinations as 4-3-2-2. The danger lies in a possible situation "set against set", and usually it is impossible to make nuts straight on the flop with these cards. If you ever decide to play this hand, then only if you are on big blind and no one made a raise, or from late position, making the minimum call.

Size of bets in Omaha poker

How to determine the size of your bet in pot-limit Omaha? It is abundantly clear that you bet size of the pot, if you have a good hand. The concept of constructing the pot, used in pot-limit Hold'em, is not applicable for pot-limit Omaha, because pots banks in Omaha are formed automatically.

Frankly, nobody raises less than size of pot. You'll never see that in the bank is $ 500, and somebody bets $ 100. "In other words, you do not have to make a small bet, to win a big pot. But from time to time many bad players do this. Their small bet contains a hint. They show that they have a powerful combination, and they want you to call their bet. Inexperienced or weak player, who fears that he will not receive a call, can bet $ 100. But if you do the standard bet, rather than adhere to any complex system, your opponents will not know on what you play, comparing the size of your bet and the strength of your combination.

Remember, in pot-limit Omaha pot will always be large enough

Remember that pot-limit Omaha always form a sufficiently large bank. You do not need to build it before the flop - it will form itself. This game will pull money from you before you know it. You play, win four or five small pots $ 500 or $ 1000 each, so that now in front of you is $ 4000, but you can put down all $ 4000 in the pot before the flop in the next deal on a decent hand!

Outs in Omaha poker

Now let's talk about outs in Omaha poker. Out is a card that can come on turn on river and bring you win. Consider example from previous post. Player 1 has A♠A♣7♦2♠, second player has K♥J♥T♦9 ♠.. Flop is A♥Q♣4♥. Player 2: has 17 outs: 9 hearts, 3 kings, 3 jacks and 2 tens.

But how to calculate the probability of winning knowing number of outs?  First let's see how it's done only with one card to come (i.e. after turn). We know that deck consists of 52 cards. Four of them are our hole cards and three are on the flop, that's why we don't know 52-4-3=45 cards. And probability of winning having 17 outs is 17*100/45%=37,78%. In general probability of winning with one card to come is n*100/45%, where n is number of outs.

When there are two cards to come (i.e. after river) it's a bit more complicated to calculate probability. Let n be number of outs. First we calculate probability, that none of our outs will come. So, we have n out and 45-n outs. Probability, that none of our outs will come after turn is (45-n)/45, after turn brought non-out there are 45-n-1 non outs and 44 cards in deck and probability of hitting non-out on the river is (44-n)/44. So probability not drawing out on turn and river is (45-n)(44-n)/(45*44).

And probability of drawing 1 of n outs is 1-(45-n)(44-n)/(45*44). If we have 17 outs than probability is 0,618 or 61,8%.

Below is table with outs and % of winning:

№ of outs	% of winning after turn	% of winning after turn and river
1	2,22%	4,44%
2	4,44%	8,79%
3	6,67%	13,03%
4	8,89%	17,17%
5	11,11%	21,21%
6	13,33%	25,15%
7	15,56%	28,99%
8	17,78%	32,73%
9	20,00%	36,36%
10	22,22%	39,90%
11	24,44%	43,33%
12	26,67%	46,67%
13	28,89%	49,90%
14	31,11%	53,03%
15	33,33%	56,06%
16	35,56%	58,99%
17	37,78%	61,82%
18	40,00%	64,55%
19	42,22%	67,17%
20	44,44%	69,70%
21	46,67%	72,12%
22	48,89%	74,44%
23	51,11%	76,67%
24	53,33%	78,79%
25	55,56%	80,81%

As you see you should invest as much as possible money in pot after the flop if number of your outs is greater or equal 14 (i.e. probability of winning is greater 50%).

Playing sets in Omaha poker

The presence of sets in pot-limit Omaha has no such value, as in other poker games. Feature of  pot-limit Omaha is that when five cards are opened, almost always someone has either straight, or flush. You can form a set on the flop, even the top set, and lose big amount of money if you call raises.

Consider the following situation. Player 1 raises pre flop with A♠A♣7♦2♠, second player calls. Flop is A♥Q♣4♥. First player raises and receives re- raise. What would you do in this situation? Some of you fold, some go all-in. Assume you go all-in, second player calls and shows his cards  K♥J♥T♦9 ♠. It's very strong hand with this flop. Second player has 17 outs: 9 hearts, 3 kings, 3 jacks and 2 tens.  Probability of winning with 17 outs in Omaha in this example is 66, 3%. First player of course also can win if none of 17 outs will come or if he draws to full house. But probability of drawing full house is much lower – only 37, 8%.

As you see sets in Omaha are very dangerous to play.

Youngest set

If top set you should play very carefully, then, of course, youngest set you have to play very, very carefully even on flop without straight and flush draws, except when you play one on one, because top set can beat you.  Let's say the flop hits J-7-3 and you have set of threes. One player starts to attack you. What will you do with this hand?

If someone makes a bet in Limit Omaha Hi, and you make raise, in some cases, your opponent folds, and in some - calls. However, assume he makes re-raise. Does this mean that he will beat your combination? Now you should use all you skills in poker. However, whether he'll beat your combination or not, you still have to play...  

However, this is limit Omaha.

In pot-limit, if you raise to increase money in pot, your opponent can do enormous re-raise. So what will you do in this situation?  You may play this hand on flop but you shouldn't make a raise. If you make a raise, and receive re-raise, probably your set of threes is very bad hand, so be very careful if you have youngest set on flop.

Implied odds in Omaha poker

Implied odds is amount multiple of stake on the table that you are going to win, if flop has necessary cards, and your opponents will not read your cards and invest good money in pot. - In pot-limit Omaha, many combinations have higher implied odds than in limit Omaha.
Sometimes you will win giant pots, with hole cards, which are not considered good starting hands, if you play them in appropriate situations, playing with the right opponents. These cards can bring you a huge amount of money. In this regard, pot-limit Omaha is similar to no-limit Hold’em in terms of that if you have a youngest pair, with which you can continue the game by paying a little or making a small raise, then the implied odds of such hand, which you will not play if flop is not suitable for you, are huge.
Suppose you have a 9-8-7-6 or 8-7-6-5, but you know that your opponent has some high combination. You can call a small bet. You can also make a small raise before the flop on these cards. Remember that pot-limit game starts with a small pot, and the serious money will be on the table only after at least two rounds of betting.
In summary, I will say that you can call the minimum bet or a small raise, having four linked cards, which will not be the best hand at the moment. In fact, you are sure that your opponent, enough solid player, has high pair, and also you know that your cards are not connected with his hand. To see the cards on the flop, you do not need to sell part of your body, you can simply call a small bet or raise. Your opponent does not know for sure what cards you play, but you know all about him. Your hand has high implied odds.

Structure of stakes in Omaha poker

Omaha High is very dispersive game that's why it eats up a lot of money.
For example let's take the game in which the blinds are $ 25 - $ 50. According to the description game doesn't seem very big, but there are always decent amount of money in the pot.
If you raise 125$ and one player has called $ 125, and another has called $ 125, now the next player can call these $ 125 and make a raise up to $ 600. If all four make the call $ 600, the bank has $ 2400, and the next bet on the flop will be $ 2400. If there is game on the flop, and someone calls, then multiply that amount by three, and get $ 7200 in the pot on the flop. You understand how this game can tear you to pieces in terms of money.
Stakes in pot-limit Omaha increase in progression, but it's very interesting to play this game, and if you really want to play, in this kind of poker you will find people who will be in play with very strange combination. This is one of the reasons why pot-limit Omaha has more multi pots compared with pot-limit Hold em.
Pot-Limit Omaha is the best game to make money, but it is also very complicated.
Many players often run risks and lose more money then they planned to win. This is the biggest mistake of the most players.
When you win not much money, you stop to play. When you lose, you lose almost all your bankroll. In pot-limit Omaha, it is very easy.
That's why you should be disciplined, playing pot-limit Omaha. You do not have to lose absolutely all your bankroll in any poker game, be it Omaha or Hold'em, or something else, unless you do not play last money. The idea is to finish the game and play again another day, give yourself a chance. But there are players who are doing it again and again.
Many people think that if they once played badly, but returned their money back, they can do so every time.
Remember that one of the main quality of professional player is discipline.

Omaha poker. Introduction

Pot limit Omaha is the largest game today. With the equality of the blinds size of pot in this game is three four times bigger than pot in the pot-limit Hold'em. And usually in a casino pot-limit Omaha is also considered the biggest of all games. Blinds should be equal to about $ 15 - $ 30 or even $ 20 - $ 40 in Texas Hold'em, and $ 5 - $ 10 in Omaha, to fairly compare the size of the two games.
This is perhaps the most treacherous poker game from all games, but at the same time it provides the opportunity to earn good money. If you're lucky, and you catch good cards on the flop, and moreover play them correctly, then in Omaha you can win as much as you can not earn in any other game.
Pot-Limit Omaha - the only poker game in which you can fold formed on the flop nuts, and you will be right. Also in this game might be a situation when you make top set on the flop, and if board has two suited cards and two connectors, you can run big risks. But since it is the combination you should play further, you will continue, and in most cases, your hand will be "killed".

Main principles of winning in Omaha poker. Final part

Going on tilt
For the player it is very easy to go on tilt when he has a row of bad beats. Anyone who has ever played poker went on tilt in any given moment. The idea is not to repeat your mistakes - if you have gone on tilt ten times, do not do it in eleventh.
For professionals the easiest thing in the world - is to play poker, get up and leave at some moment. You just should say: "Today is not my day, tomorrow will also be game" and leave.
You should always set a limit on amount of money you can lose. I know that some experts argue that regardless of whether you win or lose, you have to stay in the game if you play well, and if the game is prospective. But almost always you will have a play the next day.
Importance of mood
It does not matter what game you play, but when you sit down at a table, you must have a positive mood, and you should know that you can play well. Just make yourself to play great. If you have a desire to do something that, as you know, you should not do, listen to your instincts and leave the idea.
Our knowledge, our instincts, derived from many years of experience. Your first instinct will likely be true in most cases. But if you try to convince yourself that you have the best hand - think that opponent has combination that you will be able to beat - you - just a fool, and you don't have any chance to win in poker.
For example, on the flop - the king and ace, and you, two eights, and you think: "Well, he may have two sevens, so I call, and we'll see ...". If you think this way, you should better give up playing poker and look for a different profession.

Final remarks
Now, when we have talked about some basic principles of winning game in Omaha poker, we will tell you about some specific tips about how to win in Omaha. We will describe both the strategy in cash game and game tactics in tournaments.

Main principles of winning in Omaha poker. Part 5

Problem hands 

Excellent hands are played automatically, and terrible hands are also played automatically. What matters is how you play a marginal hand, which may be the cause of your winnings or bankruptcy in poker. Problem hands are means of existence for the player. Vitally important decisions taken at such hands distinguish real champions from amateurs.

Anyone can play with a powerful hand or on a powerful flop and win the pot. And most of the players can recognize bad hands and get rid of them cheaply. The decisions you make on average hands distinguish men from the boys, and women from the girls in the poker world. And in such situations, you either lose or win major sum of money.

You might get a very good deal, when the cards are dealt very well for you, or you might get a very bad deal, in which you have not caught a single good card. And you can lose on good cards, playing with a player who has better cards, for example, when a situation is "set on set”, and your set is youngest, or when you put all your money on a set or two top pairs, and your opponent hits flush on the river and wins, or when you have flush, and opponent improves his combination with help of river card. That's why bad players sometimes win deals against very strong professional opponents. But this is what makes the less experienced players to play again.

In all poker games you'll be rewarded for making correct decisions (in the long run). Play with the marginal, average hands that requires from player to have certain abilities, distinguishes winners from losers. What exactly will you do if you have made two top pairs on the flop (in Omaha such hand can have crucial importance). It is important to distinguish between situations where you have to keep playing, because the chances are great, and when immediately fold such hand.

Alternatively, suppose you have a possible flush from King, the second nuts flush, and your intuition tells you that you are playing against the nuts flush. A strong player will fold this hand, and the weak can not resist the opportunity to make the second-highest flush. And when it comes to showdown, he loses even more money.

Have you heard about a farmer who lost three farms, trying unsuccessfully to catch the card to the gut shot straights? And then he lost the fourth, when once again tried to catch the card and still caught it...

All the same principles apply to Omaha. Persistent failures in making only the nuts combinations or inability to recognize when your possible combination younger than the nuts, but still - the best in this situation ... Here then comes skill. Knowing that a possible flush from King - the best flush in deal, and when you make it, then possibly flush from Queen will pay you, requires great skill. As well as knowing that your hand with two top pairs - the best, and assuming measures to protect your hand, that exclude opponents from the game. These solutions bring you profit on a long distance.

Weak player remembers only those cases where he was able to make some combination. Bad players have selective memory. They forget when

• they couldn't make a combination, and 

• could, but still lost

Omaha is very unpredictable game. This means that a weak player can play any cards, can catch enough good cards or accidentally make enough combinations in separate day in order to have a very successful individual winning playing session. But loose game in the long run practically guarantees horrific results, with consequent inevitable losing.

Main principles of winning in Omaha poker. Part 4

Straights in Limit and Pot-Limit Omaha

In limit Omaha you will play such situations that even don't consider in pot-limit Omaha. In a limit game you will call raises with more specific hands than in pot-limit game. If you make nuts straight on the flop in Omaha hi-limit, you'll play further, even if flop has two suited cards, while in pot-limit, you will drop these cards in pass, if someone makes a raise. 

Of course, you shouldn't pass, if all flop cards are of different suits. If you have nuts straight on the flop in this situation, and someone raises, then most likely, he has set, since it is obvious that on the flop it is not possible to make a flush. In this case, you are a favorite (since he can only win if board is paired) and can play further. 

The idea is that in limit Omaha you will play with the nuts-straight, even if flop has two suited cards, because it will cost you one bet per round. But in the pot-limit Omaha, it can cost you a whole stack in one round, if pot is sufficiently large. Thus, the main difference between the two games is the choice of playing combinations, made on the flop.

The role of the position 

Position is more important in pot-limit than in limit Omaha. In Limit games, you know that players call bets having draw combinations, and they will call again on fourth street.

But in pot-limit of such things do not happen, because making of possible combination can cost too much. Basically, the main difference between limit and pot-limit Omaha is how many times you'll get to the fifth street in a limit game, compared to how many times you'll do this in pot-limit. 

Also, limit Omaha has always more multi-pots, while in the pot-limit games is great probability of  heads-up play or play between three players at most (it's very rare in pot-limit with a big pot when more than three players remain in game before fifth street). Either hitting the flop or hitting a draw to the nuts is more important in pot-limit games than in limit. 

Top and lowest pair

With a combination of top and lowest pair made on the flop, you can play against one opponent, but if there are more opponents then for Omaha it is not that sort of situation in which you can call a bet. And even more you do not need to play the two lowest pairs. The two lowest pairs in any form of Omaha bring death and destruction.

Suppose you are playing Limit Omaha, with hand with “dangler”, K-Q-J-2, and the flop comes K-8-2. You have a pair of kings and a pair of deuces on the flop, top and lowest pairs. If someone makes a bet, you call and get re-raise, there is a great possibility that you are playing against set, or at least, kings and eights. Then you have troubles.

Even if you have a hand with a made pair, and you have made the youngest set on the flop, you should be ready to throw the cards, if you will be placed get raise. That's why lowest pairs can lead you into a world of misery, if with their help you will make a set on the flop. In Omaha sets are much more common than in other games. A situation "set against set" is a common thing in Omaha, while in Texas Hold'em is relatively rare. If you play in pot-limit on big money, then you absolutely do not need to play game having only the youngest set.

Main principles of winning in Omaha poker. Part 3

Getting into the flow

Someone once suggested constantly ask yourself following question: "If I make a combination, will it be winning? » This is an excellent rule for beginners, but I think that after acquiring some experience, everything should start to come to you naturally. Answers to such questions - this is what you need to know beforehand; all this should come to you during the game. You must not falter and think "If this card comes, then I'm OK, and if this card comes, then things are in a bad way." As long as you can not play any poker game, maintaining a smooth pace, you can not win. 

I never think about my hand. Period.

And I do not care what kind of game this is. I always do all naturally, because I'm playing cards. Good players surely will "read" you; they know how to "read" opponents. But if you always play with a uniform rate, they will not be able to "read" anything. They may think that something is known to them, but are not sure. 

Playing bridge, you must have three or four stored skillful moves. You need to learn to play poker the same way. Everything should be in your head - if comes one card, I'll make one, if comes another, I'll do another, and if neither of them comes, I can not do anything at all - to make a quick move, when flop comes. You should always play in front of yourself. "Immediately after opening of flop, you need to know how you're going to play your hand until the end of the deal, depending on which card will be on the table after flop. 

Raises in pot-limit Omaha

In any tournament of pot-limit Omaha, there are no hands, on which you can make a raise pre-flop. I do not say that you shouldn't re-raise on double-suited aces to knock out the one remaining player. If possible - of course, you can do it. But whatever hand you have, you will rarely make the first raise. Do you know how often players lose in tournaments and cash games, having a pair of aces? - Unimaginable amount of times! 

You see, this first raise will never be large enough to "squeeze out" opponents. They know that you have, in most cases. That's why I make a raise in cash games on T-T-9-8, for example, from late position, I want them to "read», that I have aces. And then I want to flop average cards, and then see what happens.

If someone plays a decent hand, he, at least will call the first raise. You can not knock out with first raise, so let them make the raise. If you want to do something in pot-limit Omaha, then look at the situation this way – in pot three players are involved, one of them made a raise, and other two has called. At this point there are enough money in pot, so you can "squeeze out» all of them, or all but one, if you make re-raise, equal to the value of pot. You see, pot must be large enough in pot-limit, to allow you to invest enough money in order to knock out other players from deal. That's why I think that for a good player no hand has a large enough value to make the first raise in pot-limit Omaha.

Main principles of winning in Omaha poker. Part 2

Danger from Dangler

Many people play these hands, which are called "three cards with dangler. Let's say you have K-Q-J-2. Obviously, the deuce doesn't link with other cards - this is dangler. But you can see how many people play with hands of this type, even a lot of good players in big games. They know that they have three high cards, which can have a straight, nut full house or top set, so they do not take into account how it is valuable to have a fourth linked card. As for me, I can not do that. I will not play a hand with dangler like K-Q-J-2, even if the king and deuce are suited, because in such situation you'll never make nuts flush. 

You should have four cards that link with each other, one way or another.  Situations in which you can view the game with three-card combination, usually consist of small banks, in late position (if you're on the button or in front of him), and when your three cards are certainly strong.

I can't put my money on such combinations (as K-Q-J-2), while in the free position. Another thing, if you are on the big or small blind. 

But let's face it - we are talking here about Omaha! Many people played a lot of combinations, and they do not always have four linked cards  ... They also play with three-card combinations. Yes, and in most cases they lose game.

Strong hands in Omaha Hi

A computer program of comparing combinations in Omaha, which calculates the percentage of winning a particular hand against the other hand, shows that double-suited A-A-K-K is best possible starting hand in Omaha High. Many people do not agree with computer. 

They think that the best possible starting hand in Omaha Hi is double-suited A-A-J-T. It is obvious that with such a hand you can make more straights than with A-A-K-K. Of course, you will not have the three kings with A-A-J-T, but the only thing that gives you the presence of K-K  is an opportunity to have three (or four) of kings. A-A-J-T nullifies the force of the Kings in such way that with this hand there are many more combinations that will be favorites, if you make them.

If flop hits K-Q, then you will have open-ended straight and over pair. If he hits 7-8-9, you have a winning combination with the J-T. If flop hits 8-9, then you have a great open-ended straight and aces are also very strong. Practically every straight you can make with J-T and two aces, is winning, and also you can still form nuts flush in any of your suits. 

Plus, see what happens if the flop comes J-J-x or T-T-x. You have top set with a top kicker, who works for you (and over pair). And in most cases, when flop hits little pair, you have the opportunity to win the pot with aces. With flop like 7-7-2, for example, you can win with the sevens and aces. Consequently, many people believe,  that the hand number one in the limit, and in pot-limit Omaha is double-suited A-A-J-T. 

Knowledge of opponents

As in any other version of poker, playing in Omaha, you need to know the players at your table. Who will raise on bare aces before flop, unable to make a flush? Who will not? Who will raise, with only double-suited A-x-A-x? (And there are many such players). And who will raise only on double-suited A-K-Q-J?  You must know how player plays (his image and playing pattern).

Main principles of winning in Omaha poker. Part 1

One of the most important things in Omaha, that you need to learn - is that all forms of Omaha are built on the value of starting hands. That is the value of the starting hand is usually predominant in comparison with the position, which is much less important in Omaha than in limit or pot-limit Texas Hold'em.

You should always start with four cards, which are somehow linked. On the flop, you must have either the best possible combination or the possibility to form such one in order to continue play with your hand. If you have a drawing hand, then your possible combination must win the pot when you make it. If you're making flush, it must be nuts flush. If you make straight, make nuts straight. In other words, you have to make only the best combination. 

Best possible combination with backup variant

This principle, which is important in cash games and that is very important in the tournament: If you have drawing hand, then you should have a backup variant to your drawing combination – subsidiary drawing combination. For example, in Omaha Hi, you can form a top or second set on the flop, plus possible nuts flush or nuts straight. With your backup variant (or variants) in your hand it is much more likely to win than if you had just set.

Now let's say that you play in a tournament in pot-limit Omaha and formed a set on the flop, and in your hand it is not possible to form a flush or straight (no backup). If on the fourth street a card to a straight or flush is opened, than will you call a big bet to try to get a pair on fifth street? You must be extremely cautious in such situations in tournaments, when it is so important to have a backup possible combination.

Pot-Limit Omaha is the only one ever invented game in which you can form nuts on the flop, and you'll have to throw it. Suppose you have formed nuts straight on the flop and bet. If there are two suited cards on board and more than one player have called you, then it is possible that someone has set, and another, most likely, possible nuts flush, and you'll lose in this round. 

Here lies the difference between pot-limit and limit Omaha. In limit Omaha, where it cost only one bet, you have to play your hand and hope that no one will beat you. But in pot-limit Omaha you should put all your money in the pot and pray that your hand will be the best at showdown, so often the best thing you can do is to muck your hand. All the best tournament players did this a hundred thousand times.

And what about the possible nuts flush in pot-limit Omaha without backup variants? For a lot of money, it would be a bad bet, especially heads up. But if pot is big, everything can be different. Sometimes in pot can be a lot of money before the flop, and you receive call from three or four players. In this case, if you have four-card nuts flush on the flop, and somebody made a bet before you, and several of players have already called, most likely, you really very want to continue. But you should not be the first one who starts betting with such hand - you first have to check everything, because everything you have is a possible combination. 

Now you have same situation in the cash game. Here you need to call bet, when pot is great, and if you do not mind getting some more money out of pocket in case of losing. But in a tournament (except cases when you have a lot of chips and you're just trying to grab more) you just can not call, because if you lose, you'll leave tournament.

You can play a much greater number of hands after the flop in limit Omaha than in pot-limit. That's the difference between them: you can use the combination of a limit game, which you would have never used in pot-limit game, or tournament. But in both situations it is always good to have a backup variant.

Omaha Hi (PLO)

Now after we've introduced basic rules of poker, let's move to the definition of Omaha.
Omaha hold 'em (or Omaha holdem or simply Omaha) is a kind of "Hold'em", where each player is dealt four cards and must make his best hand using exactly two of them, plus exactly three of the five community cards.
Now, it is the fastest growing poker game in the  world.
Mainly, Omaha is played in pot-limit variant. That's why she is also known as Pot-Limit Omaha or PLO.

Omaha appeared in Nevada in 1982, as a lady that charmed everyone, both professionals and amateurs due to glory or despair capabilities.

At each session, from hands to hands move huge sums of money, because pots are on average two times higher than in Texas Hold'em. Involved in the game a lot of money and understanding that Omaha - is the future of poker, have created unprecedented in history of poker opportunities for earning money. 

The main reason for growing popularity of Omaha is its great attraction for the action players. These people are like big banks and short intervals between rounds of play. They overestimate the factor of luck in the game and for some reason think that the are luckier than anyone else. 

 So why it is called Omaha - after all, as stated above, the game appeared in Nevada. The reason is as follows. Normal Hold'em was played in Nevada in two forms: the popular form of Texas Hold’em, where the player was allowed to use any five of the seven cards available to him, and other more rare form, where he must play exactly two cards from his hole cards. It was this rare form that was called Omaha (she is called for some reason the Greek Hold'em). Therefore, residents of Nevada have already used the word "Omaha” in order to identify the two cards from hole cards, which must be showed at the showdown. 

When the game appeared in Las Vegas she was named Omaha, in order to emphasize the fact that must be used exactly two cards from hole cards.

In matters of gambling Nevada sets the tone for the whole world. Now you know the origin of name of four-card game from Hold’em family, which had many local names in the eighties.