When fishing the "Bob" fly in the manor Hans described, (Something I do most of the time here in Scotland) it is often not the bob fly that catches. Don't be tempted to change it though. The waked bob fly often brings fish up to it which then take the middle or point fly. Its a case of the team amounting to more than the sum if its parts.
"Political correctness is a doctrine, fostered by a delusional, illogical
minority, and rabidly promoted by an unscrupulous mainstream media, which
holds forth the proposition that it is entirely possible to pick up a ****
by the clean end"