The more things change, the more they stay the same. That’s the best way to summarize our eighth annual A-List, our effort to look beyond pure dollars to quantify the qualities that define the 20 most successful law firms. This year’s list was rife with movement: Four firms fell off the list, four joined, and six of the 13 firms that changed ranks from 2009 moved by six or more places. At the same time, we had a sense of déjà vu: Only two of the four firms joining the list this year, Paul, Hastings, Janofsky & Walker and Finnegan, Henderson, Farabow, Garrett & Dunner, are first-time A-Listers. The other two—Skadden, Arps, Slate, Meagher & Flom and Simpson Thacher & Bart­lett—are A-List veterans. Similarly, Munger, Tolles & Olson held on to the top spot for the third year in a row, with a score only two points less than its 2009 A-List total. New York–based Hughes Hubbard & Reed came in second place for the second year in a row. The difference in total score between the top and the bottom of the list shrunk, but only slightly, from 140 points in 2009 to 137 points this year. And as in past years, competition was especially stiff toward the bottom of the list: The difference in total score between firm number 11 and firm number 20 was less than half the difference between numbers one and ten.

The methodology behind the A-List is relatively simple. We look at four factors: revenue per lawyer, pro bono commitment, diversity among lawyers, and associate satisfaction. Our formula gives more weight to the first two factors: We double a firm’s scores for revenue per lawyer and pro bono, and then add scores for diversity and associate satisfaction. Pro bono was a game changer. The one unifying trend among the two A-List newcomers and two alumni was a sizable increase in pro bono scores, with healthy jumps ranging from 7 percent (Skadden) to 64 percent (Finnegan). Paul, Hastings debuted on the A-List at number ten (the highest ranking for a newcomer since 2007) with a noticeable assist from its pro bono score of 194, an almost 15 percent increase from the year before.