Why is an empty column so valuable in Spider?

In Spider you will often have to choose between turning over one more face-down card and clearing a column completely. Why is an empty column usually the bigger prize, and what should you do with it once you have one?

The rules that make it special

• Any card may be placed on a card one rank higher, whatever its suit.
• A run can be moved as one unit only if it is in descending order and all one suit.
• Any card, or any run that can be moved, may fill an empty column.
• Drawing from the stock deals one card onto each of the ten columns, and on Card Lounge you cannot draw while any column is empty.
• No card ranks above a King, so a King can never be placed on another card. The only place a King can move to is an empty column.

Put together, an empty column is the one spot on the table that accepts anything.

Three jobs an empty column does

1. Sorting suits. Placing cards ignores suit, so mixed stacks build up quickly. An empty column gives you a spare place to rearrange them into same-suit runs, which can then move freely.
2. Digging. To reach a face-down card you have to move everything above it. An empty column can take a card or a same-suit run that has no other home.
3. A base for a King. A King, or a run headed by one, belongs in a column of its own: it is the start of a complete run from King to Ace, which is removed automatically once it is finished in one suit.

Worked example: swapping two suits

Two-suit Spider uses spades and hearts. Suppose:

• Column A: 9♥ with 8♠ on top.
• Column B: 9♠ with 8♥ on top.
• Column C: empty.

Both stacks are legal, because any 8 may go on any 9, but neither is a run you can move as a unit. With the empty column it takes three moves to fix:

1. Move 8♠ from A into C.
2. Move 8♥ from B onto 9♥ in A.
3. Move 8♠ from C onto 9♠ in B.

Column A is now 9♥ 8♥ and column B is 9♠ 8♠. Both are movable runs, and column C is empty again, ready for the next job. Without an empty column you would have needed another 9 on top somewhere to park one of the 8s.

Which column to clear first

At the start, columns 1 to 4 hold six cards each, five of them face down, and columns 5 to 10 hold five cards, four face down. That is 4 × 5 + 6 × 4 = 44 face-down cards in all. Other things being equal, the shorter columns are the cheapest to empty, and a column whose cards already form a same-suit run can be cleared in a single move once that run has somewhere to go.

Before you deal

Because you cannot draw while a column is empty, every deal from the stock needs a plan. The stock holds 50 cards, which is five deals of ten, and each deal puts one new card on every column, possibly on top of a run you have just sorted. Before you deal:

• Make every useful move first: sort suits, turn over face-down cards and finish any runs you can.
• Then fill each empty column with the card or run that minds least about being covered. A King or a King-headed same-suit run is ideal, because it would end up in a column of its own anyway.
• If there is no King, a long same-suit run is the next best choice, since it stays a single unit underneath the new card.

Build in suit whenever you can

When a card has two possible homes, choose the one of its own suit: put 7♥ on 8♥ rather than on 8♠. Both are legal, but only the first makes a run that can move together later. In one-suit Spider every card is a spade, so this choice never comes up; the differences between the modes are covered in one, two or four suits.

Try it

Two-suit Spider:

• Column A: J♠, then 10♥, then 9♠ on top.
• Column B: J♥, then 10♠, then 9♥ on top.
• Column C: empty.

The aim is to finish with J♠ 10♠ 9♠ in one column, J♥ 10♥ 9♥ in another, and column C empty again. It can be done in six moves. Try it before reading on.

Answer:

1. Move 9♠ from A into C.
2. Move 9♥ from B onto 10♥ in A.
3. Move 9♠ from C onto 10♠ in B.
4. Move the run 10♠ 9♠ from B into C.
5. Move the run 10♥ 9♥ from A onto J♥ in B.
6. Move the run 10♠ 9♠ from C onto J♠ in A.

Notice how the empty column is used twice: first to park a single card, then to hold a whole run while the other run moves past it.

Practise in Spider one suit, Spider two suits or Spider four suits, and check the glossary for terms such as run and stock.