What is a magic number in sports?
The magic number is how many more wins by the leader, or losses by the chaser, in any mix, settle the race: at zero the leader has clinched. The chaser’s elimination number (E#) is the same figure seen from the other side.
How it is worked out
M# = games in the season + 1 − leader’s wins − chaser’s losses
The +1 breaks a tie: finishing level would send the race to a tiebreaker, so the leader needs one more. Each leader carries one magic number per chaser; the one quoted is against the closest club, and it falls by one with every leader win and every chaser loss, by two on a night both happen.