To estimate the others cards well you should base on several indicators. Of course, the estimation can always include some random mistakes, because there is not any method available, which gives you a guarantee, that your estimation is perfectly correct. However, this type of estimation can give you a lot of important information.
The moment you start the game is the first you can come to some basic conclusion. If all the players started without rising then you cannot expect strong cards on the fourth and on the fifth position. The reason is that players playing by the end of turn would raise, if they had good cards. The conclusion would be that the player, who opens a new turn, or one on the second and third position has a strong card. If there is somebody who had raised the cards at the beginning, you should watch this person and estimate if it is a good or bad player. If that player is rather not aggressive, then it is hard to say, what he is going to do next. If, however, the person is a strong one, and this person has opened the game, then it means that he raise because he want to encourage other to get into the game and risk.
However, if the player on the second position rises in the situation, when the game has just been opened and the winning pool is rather low, it means that the cards he is not sure the cards he has. The goal of this raising strategy is to scare away the other players. If the card of the player on the second position were in reality important, the player would have allowed other players to play, so that he could rise with his cards after they have done it before him. He should use this strategy also, when he has a very high card. There exists also a small probability, that the other players drop out the game after series of rising cards and if they have insufficiently good cards. The player that will not rise the raising of his neighbour sitting right to him, not only draw other into the game, but also he does not give away the information about his own card. Of course, there are situations, when it is highly recommended to rise. For example, when your contra-partner raises before you and when some players have already drop off the game. You should be aware also of the fact that the more raises have been done and more money invested, the more your opponents are forced to invest even more and spend their money. That’s a huge chance for you.
It means that the more rises the more correctly the players buy the cards.
The conclusion is that the more raises, the less interest the good player has to keep an Ace to another pair. If he had a straight and there is a possibility to buy one or even two cards in the same colour, he will buy it, or he will buy even four cards. If he has two pairs he will try to buy the third card to have a Full.
If a good player knows that his Full is not enough to win, he will resign and give back the pair from the Full. Instead, he will try to buy two cards to build the triangle, so that he can have a four of a kind.
Anyway, the decision about buying the new cards should be made very careful. It is necessary to take into account several factors, like your position, the number of cards your opponents buy and the character of other players. Very important is the number of cards thrown by the opponents.
You can a little bit better estimate the chances of your opponents after purchasing the cards. The number of bought cards and raises tells you everything.
A good player will know when to pass and not invest anymore his money. A rather weak player will believe that the other players want to bluff him, which turns not to be right impression.
If you pay attention to the number of cards, that other players buy, you can come to following conclusions:
1. When your opponent is buying three cards, the easiest combination will be to choose a pair and the third card that suits the other. Of course, he can buy cards trying to match them to the Full or four of kind, but you cannot be sure that it is exactly what he is going to have. Unfortunately, only later you can really say what your opponent has been planning. Then the combinations of different purchased cards seem to be easier to guess.
2. If somebody is buying two cards, it can mean only three things. First- the person, who bought it, has three cards, without the Full or four of kind. Secondly, this person wants to match the card to an Ace, in case he will not collect three good cards. Thirdly, this person tries to match cards according to the colour or street or another combination. This player does not have any chance to win. He plays just for pleasure.
3. The best combination can be achieved even by purchasing only a single card. Usually players are keen to change one card instead of three or two cards. However, the possibility to achieve great combination is as big as the possibility to play very low cards, for example straight. Especially in situations when a new card is not up to our expectations, we cannot make anything to better the own chances. In this condition, the estimation made can be wrong.
4. If the player does not buy additional cards, it means usually that he is not looking for any particular combination, but rather all of them are considered. It can be that the player does not change his cards for other reasons. For example, he has a four to kind, but he wants other to believe that he has only a straight. To do that he does not change his cards and make other believes what he wants. It can be also possible that a player does not buy any new card because he does not have any combination the new card could match. However, he does not want the pool to begin. In this way, he does not want the other to participate in the possible winning.
5. A purchasing of four cards gives in the theory the possibility of achieving of every possible combination. However, this purchase usually does not include two pairs and the partner who buys them seems not to be the aggressive type of player.
Sometimes you can estimate other players based on their cards. If you suppose that your partner has three, and you threw an Ace and King and bought an Ace and a King as well, then these cards cannot be higher than a Lady. However, if you threw an Ace, a King, a Lady, and playing two nines you buy a Jack, a Ten, and a Nine, then you can expect from your partner only three eights or lower cards. This presumption is based on the fact, that our partner could not have one of the Aces, one of the kings, one of the Ladies, one of the Jacks and one of the Nines, because we had it in our hands. The opponent has to have all the other cards to get three from the cards mentioned above. However, it is only possible when he has three cards from all the lowers than nine. Because it is not so realistic, the first hypothesis has 25% more probability.
The same way of thinking can be used also in many other situations. For example, if you have two royal pairs and eights and with an Ace, and after throwing this Ace you buy a King then you get the Royal Full. If in the same time the opponent has a Full as well, then it is very improbably that he has an Ace-Full.
All these examples have shown that the number of bought cards and the number of raises are of great importance to predict the cards of another player. Naturally, the rules described above do not apply to all possible game situations. However, in most cases the knowledge of this rule can be very helpful.