Thank you @Beyondthesea123 and @SomethingInTheWaySheCooks. As an incoming parent, I still don't quite understand. My DS has his WinColl place, a place at a co-ed Home Counties public school (where they’ve been taking girls into the 6th form since the 70s), and is on the waiting list for a full-boarding boys school near Heathrow. We loved the smaller, nurturing environment of WinColl, the personalised admissions process, a great housemaster-to-be, and it was my DS’s clear first choice so we weren’t bothered about being on the waiting list for the other boys’ school (which is undoubtedly exceptional but is potentially more problematic perception-wise). He wasn’t keen on the co-ed school for many reasons (but we needed a back-up) but did like the other boys school where he's on the waiting list. I am now trying to work out whether what we bought into by accepting the WinColl place has materially changed. Regarding the introduction of girls in order to stay relevant, I’m just not convinced. If you look at this www.best-schools.co.uk/uk-school-league-tables/list-of-league-tables/top-100-schools-by-gcse as a very rough guide, the best performing schools (independent, state) are overwhelmingly single sex – WinColl is absolutely NOT an outlier being boys only. Are Wellington/Charterhouse/Brighton really eating into their pool of applicants? I doubt it - I would venture that WinColl has never seen them as competition. I have a DD too but don’t want to shoehorn DS into a school that he’s not wild about (not to mention the huge expense) for the sake of my convenience. So I remain sceptical about co-ed being necessary for WinColl to secure the best applicants, (though I have no issue with girls). The admission of day pupils is much harder for me to understand. Winchester is already lucky enough to have a stellar sixth form college with an outstanding Oxbridge record (and no perceived public school stigma or school fees attached) – in short, a great, free, day option. St Swithun’s is a very successful, predominantly day, girls’ school a mile away. I don’t see a natural local day pupil market unless you are tempting London families down (but by 16 at sixth form boarding is much less of a big deal) as local families are so well catered for. Day children do change the culture of a full boarding school, and I am not sure how Saturday night Div works with day pupils, unless that ends too. I got the impression from WinColl a few years ago that they didn’t even see the other boys’ full boarding school as competition, so I am just very confused and can't square this. It's a big investment over five years, we don't know other prospective parents so would love to hear other thoughts.