Chambers USA has been ranking the best lawyers and law firms since 1990.   Individual attorneys are ranked on the basis of their legal knowledge and experience, their ability, their effectiveness, and their client-service.  Law firm departments are ranked on the qualities of their lawyers.  Consideration is given for the effectiveness and capability of the department as a whole – its strength and depth.  These factors and considerations are judged by interviews with those active in the market – mainly clients – and other lawyers with whom they work, and by assessing recent work done.