The NLJ 500 is the National Law Journal's annual survey of the 500 largest law firms in the US. Click here for full coverage.

The largest law firms appear to be getting smarter about what size they want to be.

In a world where size and growth is a near-obsession at some firms, many have continued to grow at a rate that is more volatile than the statistics suggest. And inversely, some of the biggest firms have decreased their footprints in a noticeable way.

That amount of movement is not always captured in industry averages. Overall, the number of lawyers last year who work at the 500 largest US law firms increased by about 2% to 163,700. The average firm size was 327 lawyers, up a hair from 320 the year before.

In comparison, only a handful of firms among the top 20 changed their size by less than 2%.

Law firm consultant Miriam Herman, who regularly advises major firms on global growth, called the phenomenon "continuous recalibration".

"Savvy firms will be adding and shedding consistent with a strategy geared to the particulars of their practice, client and geographic strengths," she added.

Baker McKenzie, the largest US-centered law firm in the NLJ 500, grew almost 6%. That change in size came without the firm completing a merger or opening a new office.

DLA Piper, the second largest firm in the survey, saw headcount decline by 4%, even in a year it acquired three small firms in Sweden, Finland and Canada.

In the two greatest swings among the 20 largest firms, Lewis Brisbois Bisgaard & Smith grew by almost 12%, while Reed Smith shrank by more than 5%. (Dentons, which is based in the US and claims to be the world's largest firm, is not included in the NLJ 500 survey because it has more lawyers in China than in the US.)

Michael Wagner, Baker McKenzie's chair for North America, said that programmes at his firm that focus more on client relationships, feedback and certain industries allow for more targeted lawyer recruitment.

At the geographic level, Bakers added the most lawyers to its Sao Paulo office last year, for an addition of 50, or more than 30% growth. The office now has almost 200 lawyers. Wagner noted how the firm is leading compliance and investigations work for several clients in Brazil, including JBS, a meat processing company facing a bribery investigation.

"No one wants to slip in their market ranking. [But] our focus is on the clients, not on the prestige, not on the reach and so forth," Wagner said. "We're just targeting our investments to things clients tell us in the market to do."

Roger Meltzer, global co-chairman of DLA Piper, called his firm's loss of lawyers in 2016 a "result of natural attrition and the constant reshaping of our professional workforce".

Even Texas firm Jackson Walker – which had 347 lawyers and 2.8% growth last year, making it a quintessentially average firm in our survey – has taken on a nuanced approach to firm size.

"We continue to believe we're in a slice of the market where we can continue to grow," said managing partner Wade Cooper. "We don't have ambition to grow outside the state."

The firm decided it was comfortable being a regional firm, and could find laterals from both national practices and locally. Jackson Walker hopes to continue to grow, but Cooper said he's not interested in doing so the classic way, via merger.

"Since our last strategic plan, my instructions are not to entertain any [merger] conversations," Cooper said.