Accurate bidding is key to winning a game of Spades. And in Spades, your success at bidding rests largely on knowing how to value your cards:

• You count all aces as being worth a trick to start. No surprise there.

• Count kings as worth about two-thirds of a trick, unless you also have the ace in that suit. Obviously, you can’t bid for fractions of a trick, but the point is to add on something to your sure tricks for each king. If you have the ace and king together, treat the pair as two full tricks. However, be aware that the ace-king in a side-suit (a suit that isn’t spades) of more than five cards is potentially extremely vulnerable because the danger of your opponents trumping a high card increases. In fact, you should mentally devalue any ace or king in a side-suit.

• Queens are difficult to value unless other court cards support them. Queens are worth something — but not much. With an ace, treat the combination as 1-1/2 tricks; with a king, treat the combination as worth a full trick. Otherwise, treating a queen as about one-third of a trick is about right, unless it’s in a side-suit of more than five cards, in which case you may discount it altogether.

• Valuing jacks, unless they’re combined with other high court cards, is very risky business. Because a jack is unlikely to win the first or second round of a suit, and because someone may be out of the suit by then and be able to trump your winner, counting jacks at all is pretty optimistic.

• Trump cards (any spades) are all valuable; count any trump card after your first three as worth a full trick. You should value all significant trump court cards, such as the ace, king, or queen of spades, at a full trick.

• Whatever the suit they’re in, all high court cards (A, K, Q, J) in a very short suit (meaning you don’t have many in the suit) become less valuable because your flexibility is impaired. A king on its own (also called a singleton) and a doubleton queen (one in a two-card holding) can both be wiped out very easily. For example, when someone leads out an ace in that suit, you have no choice but to play your king under it if you have only one card in the suit.

• If you have a void in spades, take off something from your hand valuation — your side-suit court cards are now more likely to be trumped.

Hands generally fall into one of two categories: balanced hands, which have two to four cards in each suit, or unbalanced or distributional hands, which have some suits with plenty of cards in them (a long suit) and some suits where you have very few cards (a short suit). The more distributional your hand, the higher the danger that your high cards in the side-suits won’t score tricks. For example, if you have Ace of Hearts and only one other card in the suit, everybody else is likely to have at least one heart. But, if you have five clubs, including Ace of Clubs and King of Clubs, counting both as sure tricks is dangerous because one of your opponents may have only one club and trump your winner by playing a spade on it.