The thing is, someone has to make sure the breakaway isn't 6 minutes, or 9, or 15. I've often seen Sky in that position near the beginning of the race when watching live but it never gets in to the highlights (or a brief 'and Sky did some work' mention which doesn't really reflect it). Arguably they should be hoping someone else is doing that (Etixx today I'd imagine) but their ethos does seem to be to do it if no-one else is looking tempted and that appears to be reflected in their numbers come later on. I don't know if it's just poor tactics, or if they work on the idea that they are going to have less people come the end, so they need stronger people. It can't hurt that they focus so specifically on GC, so being able to win the stage isn't important. Well, can't hurt until they lose their GC contenders and then aren't really set up to do anything else, which has happened a bit of late.