The Amersham/Chesham/Little Chalfont corridor in Bucks is one of the most tightly-contested grammar areas in the country, with Dr Challoner's Grammar and Chesham Grammar at its heart.
The year in shape
Bucks operates a strict 121 cut-off across the county. There is no super-selective tier — meet 121 and you enter the catchment ranking; miss it by one mark and you receive no automatic grammar offer.
Practical catchment for Dr Challoner's Grammar in oversubscribed years rarely extends beyond the immediate Amersham postcodes. Sibling links are common and reduce open places further.
Term-by-term plan
Autumn term. Autumn term of Year 5 is the time to start systematic GL Assessment practice. The Bucks STT format is GL across all subjects, with a single combined test morning in mid-September of Year 6.
Spring term. Spring term focus on pacing — Bucks STT papers are timed tightly and many otherwise-strong candidates lose marks to incomplete papers rather than to wrong answers.
Summer term & holiday. Summer holiday: full timed papers fortnightly. Build a clear sense of where the child sits relative to 121, and adjust the final-month plan based on that gap.
Topics to prioritise
Highest-leverage topics for the 121 line: GL Maths fractions and ratio; GL English inference; and the harder VR types (codes, complete-the-sum). Marks gained here are marks above 121.
Common mistakes parents make this year
The most common parent mistake here is over-focusing on Dr Challoner's alone. The Bucks system rewards a deliberate preference list across multiple grammars; listing only the hardest school is risky.
Signs to look for
Signs the year is going well: child scores consistently above 121 on practice papers, has strategies for the harder VR types, and approaches the test calmly. If these signs are present, the year is going well; if they are absent, the issue is rarely intelligence — it is usually pacing, format unfamiliarity or the wrong tutoring relationship. Identify which and adjust deliberately.
Where to go next
Read the Bucks county guide for the calendar; read the GL format guide; and budget for one or two mock test sittings in autumn of Year 6 to confirm pacing. Read across the related guides on this site — the guides index groups them by category for easy navigation.