The question of when to pass spade face cards is a hard one. Of course, one never wants to be stuck with an unprotected Queen; on the other hand, one also doesn't want to get stuck taking the queen with the Ace or the King.

Statistics can give us some insight into what to do, when. There are a total of thirteen spades, of course -- a little more than three per person in a four-handed game. If we believe that spades will be normally distributed in any given deal -- and things are overwhelmingly normally distributed in nature -- then we can learn that the mean number of spades a player will hold is about 3, with a standard deviation that's probably about 1. That means that there's about a one out of six chance that any given player will have more than three spades, or nearly a 50-50 chance that at least one player will have more than three spades. Worse, if you have four spades, there's a more than one-out-of-four chance that another player has at least four spades.

Now, we know a player with the average of three spades probably won't be passing you any spades, and neither will a player "long" in spades -- in fact, you're unlikely to be passed spades at all, unless you get the Queen or perhaps both the King and the Ace. You just can't count on getting any "good" spades other than what you have in your hand.

What does this mean? It means that if you hold on to that Queen every time you have four spades, you'll have your Queen flushed about one out of four times -- that's like automatically getting three points every time you're dealt the Queen. So pass the Queen if you have less than four "additional" spades protecting it.

Now, most people won't follow that rule -- they'll hold onto the Queen with just three other spades in their hand. That means you'll only get passed the Queen when the person dealt the queen has three or fewer spades -- about 15% of the time. That means that, if you have three or fewer spades and one or more of them is the King or the Ace, you'll make a little less than two points per hand from being passed the Queen and having it flushed (less, in fact, since this computation doesn't include the possiblity that the person you pass your King and/or Ace too takes the Queen).

So clearly, we learn that we shouldn't try to defend the Queen with three or fewer additional spades, and, since we're not going to count on successfully defending it, we aren't going to even try to -- we'll pass our King and Ace, for a net gain of a little more than one point every time we have a Queen or an Ace or King. That adds up after a while!