Counting points can sometimes be the key to winning or loosing. When you are looking to set an opponent or simply make your bid, being aware of how many points you have, how many points are still out there, and how many you are wiling to loose is what will make you win or lose close rounds.
When you are aware of how many points you can lose and still make your bid, it allows you to throw away some potential tricks that you might be considering trumping. Also, if you are aware of how many points you need to set the opponent, it will help to know how many points to sluff to your opponent. For example, if you have a 10 and a 1 in your hand, it may be worth throwing the 1 on your opponents winning card rather than the 10 if it is all that is needed for setting your opposition.
Simply remember that the difference between making your bid and being set is often only a matter of 5 points, so manage your points wisely and you will be on your way to a winning strategy.