Let’s create a term. Each time a lawyer in a law department asks a partner in a law firm (a firm, for simplicity) to handle a matter, when that particular lawyer has never instructed that firm before, let’s call it a “first instruction.” Thereafter, if that same lawyer asks the same firm to do something else, by definition it is no longer a first instruction. Another lawyer in the department, however, might retain the same firm on a matter and that would also be a first instruction if the lawyer had not previously engaged that firm.
My hypothesis is that during a year, the number of first instructions by a typical law department is a very small proportion of all the matters sent by the department to a firm. Most in-house lawyers have a handful of preferred firms and they stick with them (See my post of March 6, 2007 about loyalty to firms.). I would not be surprised, in fact, if less than five percent of matters were new instructions. Most of the new instructions, I suspect, would be by the general counsel or another senior lawyer.