When I lived to the west of Huddersfield as a student in the 1970s I was the resident bus expert. I told my flatmates that as well as the Marsden buses (50-52) they could catch the 8/9 Hill Top/Wilberlee service along Manchester Road. What I didn't realise was that half of the buses went via Crosland Moor and I incurred the wrath of the lads when they caught the wrong one.
This was NOT a case of catching either the 8 rather than the 9 or vice versa, the different numbers determined the terminal point (short workings having a separate number), but it had never occurred to me that a single route number could go two different ways. I believe that the buses allocated to the 8/9 therefore had to be those which displayed an intermediate destination as opposed to the "town" buses which only showed the number and the terminus.
Another quirk was that if you walked up/down the hill from Milnsbridge you could catch any of the Golcar, Slaithwaite, Scapegoat Hill or Meltham via Helme services although these were complicated also, being circular/ figure-of-eight routes and understandably the other lads didn't quite trust me and stuck to the Marsden buses following the above debacle. Which was a pity as although these routes were all one-man operated by this time, peak period extras brought out lovely old back-loaders with conservative Huddersfield styling.