How many matches does your club league have

Ten teams signed up to the club league, and whoever is organising it always asks the same thing first: how many matches will there be? Everything else follows from that — the pitch hours, the weekends it fills, the referee.

You do not need to look it up anywhere. No federation publishes this: you work it out. And the sum is shorter than you would think.

Where the number comes from

In a round robin, each team plays the other nine. Ten teams times nine opponents is ninety, but that counts every match twice, once for each team playing it. Divide by two.

Ten times nine, divided by two: forty-five matches.

The formula for any number of teams is the same: the number of teams, times that number minus one, divided by two.

Ten teams means forty-five matches and nine matchdays. Nobody publishes that figure: you calculate it.

First, a decision: one round, or home and away?

This is the decision that changes everything, and it is not a matter of taste. It depends on where the league is played.

If the whole league is played at your club, it is a single round. There is no home and away: every match is played in the same place, and without home and away a return fixture means nothing. Forty-five matches, nine matchdays.

If the league is between clubs, each team has its own ground. Now home and away do differ, so every pair of teams meets twice, once at each ground. Ninety matches, eighteen matchdays.

The catch: an odd number

This is where clubs get caught out. On each matchday teams are paired off two by two. If the number of teams is even, everyone plays. If it is odd, one is always left over.

With eleven teams there is no way to pair them all: one rests each matchday, and they take turns. Which means it is not nine matchdays, nor ten, but eleven — one per team, so that everyone gets their turn to rest.

And the matches go from forty-five to fifty-five: twenty-two per cent more, for one extra team.

The count, team by team

The reference everybody knows

The Spanish Liga EA Sports has twenty teams. Each team plays thirty-eight matches: nineteen at home and nineteen away.

But careful, because this is the most common confusion: those thirty-eight are one team’s matches, not the league’s. The whole league is three hundred and eighty, ten per matchday.

When somebody tells you "a twenty-team league is thirty-eight matches", you know they are talking about a team and not about the competition.

What your club decides, not the arithmetic

Everything above is mathematics and is not open to argument. What comes next is not settled by any number.

How many pitch hours each matchday costs and how long a match lasts depends on your facility and the age group. How many cards bring a suspension is set by each regional federation. And whether you play home and away is decided, as you have seen, by where you play.

The sum tells you how many matches lie ahead. The calendar, from there on, is yours to build.