My visits to London get fewer and fewer, regrettably. because of other commitments but I can and do from time to time follow what is happening in a particular part of London by focussing on a bus stop via the internet and seeing what is being displayed there on the 'next bus' screen. As I stay with my sister when I am in London and she has lived in the Streatham/ West Dulwich area for decades, in different properties, I tend to focus on the routes I use when I visit her. The 3 and 159 nave been the routes I've been most interested in for a long time, and they do of course serve the same ground between Brixton and Oxford Circus, save the bridge they each use to cross the Thames, although even that was the same for many years. I noticed a year or so ago that when I looked at stops in Kennington for instance, both northbound and southbound, that on the whole the 3, operated by Abellio from their Battersea garage, seemed to run a better service than the 159, operated by Arriva London South from Brixton garage, both in spacing of buses and whether any were being turned short, both based on the advertised frequency, the 159 being generally more prolific. However, when I visited the area, at a time when my sister lived with a bus stop for the 3 outside her house, I found that in practice I could wait at Piccadiily Circus for a direct no. 3, having let two or three 159s go by, and find that the Crystal Palace bound no. 3 would suddenly on arrival at Brixton police station be pronounced as turning at the next stop. This was more than frustrating, even for someone like myself not paying for the journey. This curtailment would not have been flagged at the preceding stops, whereas I noticed 159s leaving Streatham were already being shown as turning short at Oxford Circus, Trafalgar Square, etc, Now Abellio have the 159 too, and I do wonder whether the reasons they have acquired it are as above board as they should be. Are there many more late -announced curtailments than previously? I don't know, and please don't think I'm getting at Abellio, it's just the example I'm most aware of.
Every operator will put a gloss on their performance, and stats can always be manipulated, as every politician worthy of the name has always known.