The ACC Docket, Nov. 2010 at 12, includes findings from the most recent Serengeti survey. Pay attention to the definition in the one sentence: “Many in-house counsel believe that convergence (i.e., reducing the number of law firms with which a company works on a regular basis) is an effective way to control legal spending.” On a regular basis? I use the term “convergence” to mean a marked reduction in the number of all law firms used, not just a reduction in the regular stable of firms.
A law department could concentrate its spending on fewer key firms but still retain hundreds of other firms for specialized or localized needs. In my dictionary of law department terms, that would not be called “convergence,” but might be called “concentration.” I happen to favor concentration of spending and care little about the total number of firms retained (See my post of Dec. 29, 2009: UTC and 13% get 75% of the spend; March 29, 2010: Dynegy’s concentration of legal spend; and May 29, 2009: measures of law-firm use concentration with 9 references and 1 metapost.).