Some firms are better than others in advancing women to partnership and keeping them there. Though they vary in size, culture, compensation systems and history, the most successful share a higher than average percentage of women in leadership roles, the support of top leadership and a high level of grass-roots involvement.

Reed Smith may have one of the most ambitious programs in the country, though the percentage of women in equity partnership at the firm—22 percent in 2014, up from 15 percent in 2008—doesn’t capture all that’s going on. Over the past seven years, its women’s initiative has launched a progressive assault at each rung on the career ladder where its women lawyers have tended to get stuck or drop off. Kit Chaskin, Reed Smith’s longtime global women’s initiative chair, says the firm’s goal is that women occupy half the ranks at every tier.