I presume that the catchment area for your school of choice is very small.
The usual criteria for admissions is
siblings first
then in catchment area
then distance from the school.
It will also depend on how many children the school are 'allowed' to take in each yeargroup.
As a side note, I actually 'registered' my interest for my first daughter to go to the school about 2 years before she was able to start. It was never really unlikely she would get in as it is a small village school and we only live a couple of hundred yards from it but some years it can be difficult.
This year we have ahd parents who live within a mile of the school have to appeal to get in becuase there were so many siblings starting that there were only a hadful of spaces left. They got in on a technicality (the LA measured to the wrong place

).