Right now, in more than half a million homes across the country, parents of 10-year-olds are agonising over secondary school admission forms. With just days left to decide, some of the old assumptions have been turned unexpectedly on their head.
For too long we have taken for granted that the school system in our cities is failing, nowhere more so than in London. Indeed 'inner-city school' has become a byword for poor results and out-of-control behaviour, forcing families to flee to the suburbs or the shires.
Except that it is no-longer true. As London's schools pull away from the rest, what on earth has been going on? And what can other regions do to copy it?
Inner City Success Story
Take the common measure of performance, the proportion of children gaining five good GCSEs (including maths and English). In 2007 London overtook the South West region, in 2008 it surpassed the results of East of England, and then in 2009 - extraordinarily - London overtook the South East to become the best performing region in England.
Inner London's Schools: From Bottom of Class to Star Performers
Since then it has pulled further ahead (despite the dip this year with the GCSE English "regrading" row), with the rise driven in particular by the transformation of Inner London, from bottom of the class to star performer. Of the 107 secondaries in England that are "failing", only three are now in the capital.
Of course different areas have very different characteristics which affects results hugely. But on the most common measures (proportion with English as a second language, or that qualify for free school meals) London has amongst the most "challenging" school intakes in the country.
In the words of Chris Cook in the FT: "There is, quite simply, no better place in England for a poor child to get an education." Indeed a recent study by the Education Endowment Foundation found that London schools were outperforming across the range of ability.
Nowhere illustrates this turnaround better than Ministers' new poster-child, the Burlington Danes Academy in West London. (At this point I should declare an interest, as this was my own school, a very long time ago...)
Eight years ago Burlington Danes was failing and put into special measures. Now, under the remarkably performance-focused leadership of Sally Coates, results are rocketing and last year it was nominated for the TES "Outstanding School of the Year" award.
Remember this is a school where, according to OFSTED, 40% of pupils speak English as second language, and nearly half are eligible for free school meals. Its catchment area - rapidly shrinking as it becomes more oversubscribed - includes some of the most deprived areas in the country.
Other formerly failing schools in London have similar, if less dramatic, turnaround stories to tell.
What's gone right?
There are no single answers, but two broad theories as to why this has happened - a "supply side" explanation that focuses on what London schools are doing right, and a "demand side" view that London has benefited from big demographic and economic shifts. There is truth in both ideas.
Many point to the appointment of Tim Brighouse as London school Tsar in 2002. The then Labour Government identified the problems in London schools as a big political issue, and focused a lot of resources and energy on the problem.
Brighouse set up the London Challenge, providing extra support and monitoring of poorly performing schools, and leaving behind a legacy of skills, people and ideas that have continued to reap rewards.
The previous year had seen the launch of Teach First which aims to get the best graduates into teaching at some of the most challenging schools. Although a national programme, most of its placements have been in the capital.
These "supply side" successes are encouraging for other regions, as it means there are ideas that might be replicated, albeit against tighter budgets. However London may also have benefited from structural factors that will be harder to copy elsewhere.
Scale is one. The huge concentration of big schools in London means resources can be used more efficiently. Alongside this is a large and liquid labour market for teachers, supported by a number of teacher training institutions. Schools in London report far more good applicants per post than elsewhere, despite the high cost of living. Rebecca Allen of the Institute of Education notes that London has younger (and perhaps more dynamic?) teachers.
The rapid growth of London's population, while putting a strain on school capacity, may also be helping to drive up standards. Those migrating to London (whether from the rest of the UK or from abroad), are a disproportionately aspirational bunch - whether rich or poor, those prepared to move to get a better job are also likely to push their children to take the same opportunities.
And the relative success of London's economy means pupils in even the poorest parts of London can see for themselves the benefits that a good education might bring them.
One interesting consequence of the turnaround in London's schools may be on out-migration. Traditionally young people have come to the capital to start their careers, but left to start their families. There is some evidence that this pattern is shifting, with more parents choosing to stay put and bring up their children in London.
Time will tell whether this is just a temporary effect of the housing market slowdown, but right now boroughs across London are reporting dramatic rises in the "retention rate". More of the children that finish at primary schools are transferring to nearby secondary schools, rather than moving away.
Few things matter more to the future of the country and its economy than education, so it's essential that the lessons of a success like London's are learnt and spread elsewhere, particularly at a time of such change for schools.
With London Challenge now finished, budgets shrinking, and the priority shifting from performance to urgent capacity increases, can the Capital's performance be sustained? Boris's recent bid for more powers over education may be a recognition of the risks.
For now, parents filling in the London school application form can be grateful that their choice is not quite as difficult as it was, while those elsewhere are entitled to ask what is being done to achieve the same across the country.