Caper Jones, in an unpublished 1977 study for IBM, found that the very best developers are much more productive than the worst programmer — when working on small projects. The best developer will complete a 1k line of code (LOC) effort 6 times faster than the lousiest. The productivity delta falls to 2x on a 64k LOC project. Beyond a few hundred thousand LOC both sorts of people perform equally well. Or equally poorly.
via EETimes – The legend of the superprogrammer. I think our tendency is to stick awesome programmers on a large task and hope they can lift it up by themselves instead this argues for sticking them on small projects, on the large project they may be more valuable on a very small subset but on the whole just as important or un-important as a normal programmer.