I know people who’ve got into Crofton as in-year after a term or so waiting but they were very close (.2 of a mile). They got Southborough while waiting. If you are a distance away you will find that every time someone nearer moves to the area you will go down the list.
I posted the below in reply to another query about secondary schools from Petts Wood:
Petts Wood for secondary certainly isn't straightforward but then it also has lots of options partly due to great transport links which makes journeys short plus also on the cusp of various grammar regions. I know children who go to Darrick Wood, Chis & Sid, Townley, Newstead, St Olaves, Weald of Kent grammar, Coopers, Chislehurst School for girls, Ravenswood, The Brit School. Also private schools: Eltham College, Bromley High, JAGS, Babingtons, Farringtons, Whitgift, Colfes, Alleyns, Dulwich College.
For grammar you have three bites at the exams, for local grammars you have Newstead or Olaves. For Bexley you are usually in distance for most of the grammars and always Chislehurst & Sidcup grammar. For Kent for girls you just need a pass for Weald of Kent which has been in distance for recent years and for Kent grammars based on score you have Dartford Boys and Dartford Girls, both of which have a private coach stopping at PW. Then again for girls you have Tonbridge grammar.
For comprehensives as someone else has mentioned there is Darrick Wood (co-ed) which is generally only in catchment in recent years at the Crofton end of Petts Wood. Bullers girls (and more recently the new boys school) has been in catchment on and off and seems very random. For boys Ravens Wood is popular and well respected. For girls for comprehensives it is a slight challenge if you don't make the grammars or Darrick. Coopers (co-ed) and Chislehurst School for Girls haven't been top picks for a good while.
DD is at Newstead and has found that some of her friends who got into the school chose to move to Petts Wood after their younger siblings qualified for the school are now very happy and have access to lots of amenities. Before that it was lovely that we could be the hub for DD's friends and get to know them as apart from Orpington itself it was one of the few points that girls on the Beckenham and on the London Bridge lines