How the missing cards split

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If you and your partner hold eight cards of a suit between you, the two opponents hold the other five. How those five are shared out between them decides whether a plan works, and the chances can be counted.

With an odd number missing, the most even split is the most likely: five missing cards split 3–2 about 68% of the time, 4–1 about 28%, and 5–0 about 4%. With an even number missing, the perfectly even split is less likely than you might think, because there are more ways to deal an uneven one.

Good players carry a few of these numbers in their heads. They do not promise what will happen on this deal; they say which plan works more often.

One question

You and your partner hold seven spades, so the opponents hold six. Which way are those six most likely to split between them?

Say it backIn your own words: why is an even split of the missing cards less likely than an uneven one?

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