Nil is an extremely important bid in the game of Spades, as only the most powerful spade-heavy hands are worth more than a Nil bid. Therefore, in order to succeed, you need to know when to bid Nil, and how to play a Nil hand. In my "Art of Nil" series, I'll cover the ramifications of a Nil bid from the perspectives of the Nil bidder, his partner, and their opponents.
In general, you should bid Nil whenever your hand is suitable, as 100 points is just too much to pass up. Three main factors determine the suitability of a hand for Nil: The presence of low cards in each suit; the "shape" (distribution) of your hand; and your spade length and strength, or lack thereof.
Many casual Spades players have the misconception that high cards will ruin a hand's Nil potential. In reality, it's not high cards you have to worry about--it's the presence (or absence) of low cards. I'd much rather bid Nil with a suit holding of AKQ432 than I would holding 987--the first holding has three high cards yet is very low-risk, but the second holding is likely to be set in this suit, despite not having any high cards.
Ideally, you want to have at least one card of 5 or lower in each suit in which you're not void. If you have five or more cards in the suit, you'll often need two low cards to survive. It's okay to take a chance at a Nil with one "weak" suit (a suit without low cards, provided it's not a long suit), but if you have two or more such suits, you'd best consider another bid. Of course, this doesn't mean to bid Nil wih a Queen-Jack doubleton, but a doubleton 86, say, wouldn't be unreasonable.
Your suit distribution is also very important. If you have four cards in one suit and three in each of the others, your hand is not Nil-worthy without a whole lot of low cards; but if you're very short or void in a suit, you can often get away with risky holdings in other suits, especially if your partner learns early in the hand that you have a void. A three-card or shorter suit sans low cards becomes a lot less scary when you have a void and can discard it on another suit. In general, the more "unbalanced" your hand, the more Nil-worthy it tends to be.
Then there's your spade suit. If you have four or more spades or more than one high one, you just don't have a Nil hand, except under the most dire circumstances. Remember: Each and every one of your spades must land under a higher spade in order to make a Nil, so it's a good idea to figure out how many spades are available to "cover" your spade holding. For instance, if you hold 973 of spades, there are nine spades that you can unload yours under, with five of them available to cover your 9. If your partner's bid suggests that he doesn't have at least one-third of this total, you could be in serious trouble. Your opponents will try to deny you spade cover as much as they can, so you can't expect to unload your spades under theirs.
Next time, we'll discuss how to play a Nil hand. Stay tuned!