I understand the pressure for law firms to reduce their costs, and why this topic has exercised the profession in recent years, but for a long time I have wondered why there is so little corresponding attention paid to the other side of the equation: the ability to win work.

Businesses rise or fall on their ability to grow the top line – subject to normal caveats about pricing and the right kind of work – not on how good they are at bringing down costs. Watching the pennies is important but it ain't the magic of capitalism – especially in a field where a few pitch wins can bring in millions.

So it's important. And yet, even as a paid-up industry anorak, I didn't have a clue which law firms were great at it and which were terrible. And never have I seen any evidence that law firms had much sense of whether their peers were any good or how to benchmark their own efforts.

This week's in depth on business development has gone a fair way towards lifting my fog, though the dark arts of law firm BD still seem unnecessarily shrouded in mystery. The first point to take away is that it is clear that it has moved on a lot since the ad hoc party planners of the 1990s. Sophistication has improved, genuine specialists with industry experience have been shipped in and a fairly select band of effective operators have emerged.

That said, quality remains uneven and you still see a stark difference between what you would consider a sales or marketing professional in most industries and the typical breed in law, who often still seem rather inward-facing.

Much of that is thanks to the strange ambiguity about sales in law firms. Eighty percent of lawyers hate selling, but they still don't much like non-lawyers to do it, which means they have a lot of BD people who don't want to do it either. Weird. That lack of consensus about the role of BD, and feelings of being under-valued by partners, has contributed to a defensiveness among law firm marketeers that they should try to grow out of fairly soon. Ultimately, being benchmarked will be good news for the better BD teams out there.

One interesting observation that's been notable for a while is the marked improvement in BD among top firms. The mid-tier still do some of the most creative stuff but they don't seem to have quite the across-the-board strength or thrusting attitude of old. Many of the best BD operators were outside the City leaders a decade ago – that dynamic has changed.

Still, however you do your BD – whether through lawyers or marketing professionals – the discipline matters far more than usually acknowledged by the industry. The law firms that dominate the 21st century will have fully grasped that fundamental reality.