Lawyers know that definitions dictate outcomes. That’s why the Yale Law Women’s latest list of the “Top Ten Family Friendly Firms” includes some surprising names. At least, some surprised me.

It turns out that the YLW’s definition of family friendly is more restrictive than the plain meaning of the words. According to the survey methodology, it’s mostly a function of firms’ attention to particular issues relating primarily to women. There’s nothing wrong with that, but it shouldn’t be confused with what really undermines the family-friendliness of any big firm — its devotion to billable hours and billings as metrics that determine success. That problem isn’t gender-specific.

To compile the annual list, YLW surveyed the Vault Top 100 Law Firms. What would happen if they included all of the NLJ 250 or an even larger group that included small firms? I don’t know, but I’ll bet the list would look a lot different.

Now consider the survey categories and YLW commentary:

— Percentage of female attorneys: “Although YLW found that, on average, 45% of associates at responding law firms are women, women make up only 17% of equity partners and 18% of firm executive management committees. Additionally, on average, women made up just 27% of newly promoted partners in 2010.”

— Access to and use of parental leave: Virtually all firms have them. Big deal.

— Emergency and on-site child care: I understand the advantages, but how much family friendly credit should a firm get for providing a place where young lawyers can leave their babies and pre-schoolers while they work all day?

— Part-time and flex-time work policies: “98% offer a flex-time option, in which attorneys bill full-time hours while regularly working outside the office.” So what? I know senior partners without families who’ve done that for years.

— Usage of part-time and flex-time policies: “On average, 7% of attorneys at these firms were working part-time in 2010.” Will they become equity partners? “Of the 7% of attorneys working part-time, only 11% were partners, a number that may also include partners approaching retirement. Only 5% of the partners promoted in 2010 had worked part-time in the past, on average, and only 4% were working part-time when they were promoted.”

— Billable hours and compensation practices: “[I]t remains to be seen whether it is truly possible to work part-time at all. Our statistics indicate that while part-time attorneys appear to be fairly compensated, many may work more hours than originally planned. Most firms (93%) provide additional compensation if part-time attorneys work more than the planned number of hours or make part-time attorneys eligible for bonuses (96%). However, part-time attorneys received bonuses at higher rates than full-time attorneys (25% compared to 23% on average), suggesting that many part-time schedules may ultimately morph into full-time hours over the course of a year.”

— Alternative career programs: What’s that? Outplacement support?

All of this gets weighted according to another survey of Yale Law School alumni who ranked the relative importance of the surveyed policies and practices.

Continuing efforts to achieve greater big law transparency are laudable. But one problem with lists and rankings is that they take on a life of their own, wholly apart from methodological limitations and the caveats accompanying the results. (See, e.g., U.S. News rankings). Here, the YLW cautioned that it “remains concerned about the low rates of retention for women, the dearth of women in leadership positions, the gender gap in those who take advantage of family friendly policies, and the possibility that part-time work can derail an otherwise successful career.”

The honored firms will gloss over that warning, issue press releases, and delude themselves into believing that they are something they’re not. Someone truly interested in whether a place is family friendly should find out where it ranks on the “Misery Index.” Partners won’t tell you, but that metric would reveal a firm’s true commitment to the long-term health and welfare of its attorneys and their families.

If you really love someone, you should set them free — even if it’s only every other weekend.