Source: http://www.bridgementor.com by Shelagh Paulsson
Understanding how tricks are won at bridge will help you to understand how to evaluate your hand. Tricks are won by high cards, trumps, and long suits. If you have two balanced hands between the partnership, how many HCP (High Card Points, in the traditional 4, 3, 2, 1 method) you and your partner have between you will usually determine how many tricks you have.
Balanced Hand is a technical bridge term. It applies to hands that have no singletons and no more than one doubleton. The possible combinations are 4333, 4432, and 5332. When we evaluate these hands, most of the time we count just our HCP. We open the bidding with almost all balanced hands of 12 HCP or more. If you have 4333 distribution, or no Aces, this is reason to subtract a point when evaluating your hand.
Counting HCPs
There is more to counting HCPs than simple arithmetic. The traditional method undervalues Aces and Kings and overvalues Queens and Jacks. High cards in short suits might take no tricks, for example a doubleton QJ will take no tricks if they both fall under the opponents’ Ace and King. Supporting cards such as tens and nines matter. A suit with KQJ109 will take 4 tricks regardless of how the suit divides, while AKQ32 will take from 3 to 5 tricks depending on how many partner has in the suit and how the suit divides. However, HCPs gives the first 6 points and the second 9 points.
There is an excellent program you can use with your browser at:
http://www.jeffgoldsmith.org/cgibin/knr.cgi
The Kaplan and Rubens Hand Evaluator, designed by Edgar Kaplan and Jeff Rubens of The Bridge World magazine, allows you to enter a bridge hand and tells you how much it is really worth.
When you have a Semibalanced Hand (5422 or 6322), a hand with two doubletons, or an Unbalanced Hand with a singleton, the number of tricks you will take will be determined much less by HCPs and more by the quality of your trump fit, and the kinds of controls you have. When we have an unbalanced hand, it is better to use Losers and Quick Tricks to evaluate the hand.
Losing Trick Count
Count one loser for each of the top three cards in each suit that are not the Ace, King, or Queen. There are a maximum of three losers in any suit: three small, four small, five small, etc., are all three losers. The theory is that eventually you will likely be able to set up a trick in your long suit.
Let’s look at some examples:
No Loser Suits 
One Loser Suits 
Two Loser Suits 
Three Loser Suits 

AKQ(x) 
x 
xx 
xxx(x) 
AK 
Ax 
Qx 
Qxx(x)** 
A 
Kx 
Jx 
Jxx(x) 
void 
AKx(x) 
Axx(x) 


KQx(x) 
Kxx(x) 


KQ 
Q10x(x)* 


AQx(x) 


* without the Jack or 10, consider it 3 losers 

** without the Jack or 10 