A commonplace holds that, roughly speaking, 25 percent or fewer of a law department’s law firm’s account for 75 percent or more of all its billings. Likewise, 25 percent or fewer of a department’s matters account for 75 percent or more of its spending on external counsel during a year.
A third manifestation of Pareto’s venerable generalization (See my post of Sept. 4, 2005.) is that it may well be that 25 percent of fewer of the timekeepers on the matters of a particular client are responsible for 75 percent or more of the billable hours or the dollar value billed or both. This should hold true because to some degree the same lawyers are assigned to service the same client (See my post of Dec. 8, 2006 about core teams in law firms.).
To refine the ratio a bit more, I suspect that each of the above ratios are more like 20 percent to 80 percent, but the point is the same.