Whenever you play no limit cash games then you obviously watch your opponents. Even if you don’t think you do, you still observe their actions and what position they raised from and what their likely actions mean…….even if you don’t think so then you still watch your opponents. However your opponents also watch you in just the same way. Some will take that observation to a higher level and take precise notes and use tracking software. Even the basic players will make basic observations.
The natural knock on effect of this is that whenever you enter a pot with a raise or you call a raise then your opponents will put you onto a range of hands even if only sub-consciously. The range of hands that they put you on will be your perceived range. So then this means that you have two potential ranges. These are your actual range and the range that your opponents think that you have got. It stands to reason then that if your actual range and perceived range are pretty close then your opponents will be able to play accurately against you and make better decisions.
If your actual range is different to the range that your opponents perceive then you can only gain. For example if you raise with a 10% range from the UTG seat but your opponents put you onto a 3-4% range then two good things will happen. You will win more blinds when everybody folds and you will also win more pots post flop by being able to represent hands that you don’t have. For example let us say that you are playing in a NL200 full ring game and you raise UTG with 9c-9d.
If your opponents perceive that you range is around the 4% mark which is AA-JJ, AK and AQ then you may be taking a profitable line expanding that to something like 6% without fear of raising too much from this position. Your pre-flop raise will gain respect and if you are 3/bet from such a position then you will be safe in the knowledge that you are facing a really strong range.
This is the advantage to open raising rather than just limping in because 3/betting ranges are that much tighter than opening ranges. If you are called by an opponent with pocket tens and the flop comes A-K-4 then it will be very difficult for your opponent to do anything other than fold because of your perceived range.