What, if anything, unites the large law firms operating outside the top 50? They have no catchy group name, operate from disparate areas of the UK and deploy a wide range of management styles and practice models. And, as this week's in depth feature finds, there is no easy answer as to what separates – often with brutal force – the winners from the losers.

But perhaps the one thing they have in common is what they don't have: they really don't have it easy. Let's be realistic – the legal services market, for larger firms, is a cosy place. It went through its period of upheaval in the 1990s and now it's a remarkably stable pecking order – too stable, probably, for the good of clients.

But then, clients are partly to blame. They helped create the barriers to entry, such as panel reviews that keep the usual suspects in pole position, a lack of pressure on rates and institutionalised client relationships. Yes, it's a competitive labour market out there, but, providing they don't start haemorrhaging partners, top 50 firms can basically rub along for years with little direction and bad leadership and still get by (and a few do).

The firms outside this club must look on wistfully, for they get no such margin for error. Operating in the profession's Championship division, they face a struggle to ever earn promotion while being attacked from below by nippy challengers.

And consider what a turbulent section of the market they operate in. Without the diversification of larger firms they are acutely vulnerable to swings in local markets and core practice groups. Twists of fortune like the timing of investment decisions can likewise have a huge impact.

At the same time, the leveraged model that some use has been exposed over the last three years, with firms like Cobbetts, Blake Lapthorn and Bevan Brittan seeing eye-watering gyrations in partner profits.

But if they are united in their challenges, what common ground is there to their successes? This will sound corny, and I'd never make it as a consultant – but firms in this group have to be better. Better than bigger firms, more client-centric, tighter on operational issues, more scrupulously watchful of cash management, strategically astute and utterly faithful to their chosen practice model (though there's no particular model that 'works'). Oh yeah, and it helps to be lucky, too.

Harness all of that and you can achieve explosive growth – the momentum we discuss in the main piece. It seems that you don't have much choice but to try, because in that section of the market, if you're not going forward, you are probably going back.

Personally, I think it would be entirely healthy for the profession if more of those outfits gained their promotion and ushered a little more competition into the staid ranks of larger firms.