Of the many "best" law firms for women compilations, I find the Women in Law Empowerment Forum's annual list one of the meatiest. It's no-nonsense, focusing solely on how women fare in the power and money departments. It doesn't cover which firms offer the widest selection of affinity groups, the most creative alternative work arrangements or the best ­lactation rooms. It's all about business, baby.

So are women making it, according to the latest WILEF list? Well, it's a mixed bag. I see no reason for despair, but there's not much call to break out the champagne, either. The discouraging news is that fewer firms qualified for WILEF's Gold Standard Certification this year (42 firms, whereas 50 did so last year). The ameliorating factor is that WILEF tightened its standards.

To qualify for that Gold status, firms had to satisfy at least four of six criteria (last year, they only had to fulfill three) with respect to women:

• 20 percent of equity partners or 25 percent of the nonlateral attorneys who became equity partner during the past 12 months.

• 10 percent of firm chairs and managing partners.

• 20 percent of the primary governance ­committee.

• 20 percent of the compensation committee.

• 25 percent of the practice group leaders or department heads.

• 10 percent of the top half of the most highly compensated partners.

Frankly, I thought the standards rather lenient. How hard could it be for most big firms to meet at least four of these requirements?

Apparently, quite hard. What's notable is that some of the big firms dropped off the WILEF list this year, including: Gibson, Dunn & Crutcher; Mintz, Levin, Cohn, Ferris, Glovsky and Popeo; Ropes & Gray; Sidley Austin; and Wilmer Cutler Pickering Hale and Dorr. (It should be noted, though, that Orrick, Herrington & Sutcliffe qualified for the first time this year.)

What gives? "The threshold of having to satisfy four requirements made it difficult for some firms," WILEF chair Elizabeth Anne "Betiayn" Tursi said. A few firms were thrown out of consideration, she added, because "they refused to answer questions about compensation — which is pretty basic." Patti Skigen, WILEF's chair for the certification committee, remains hopeful that more firms will win WILEF's certification in the future, once they become acclimated to the new standards.

Tursi added that some firms might have fallen behind because some of their female baby boomer partners have retired or gone in-house. Another possibility is that some started their own firms.

Whatever the reason, one thing is clear: Women's progress in law firms remains fragile. The margin between what qualifies for "good" versus "bad" results is so small that hard-earned progress can quickly disappear.

Vivia Chen is chief blogger for The Careerist. Updates appear daily at thecareerist.typepad.com. She can be contacted at vchen@alm.com.