Best I can do is approx 10% reduction by splitting at BSK. Is this because its all in the SW region and the best splitting opportunities are when the route crosses regional boundaries?
Thanks - Morpethcurve
The best splitting opportunities tend to be where, for example, you want to do a day trip but there's no Day Return (as Day Returns tend to be priced at much less than the equivalent Period Return), or where you are starting your journey at a time where the Off-Peak through ticket to your destination isn't valid, but you are continuing until, and after, such a time where it (or an intermediate Off-Peak ticket) is valid. Splitting opportunities can also present themselves if you are travelling to or from a station that is on the 'cliff edge' of a pricing flow (e.g. travelling from Formby, rather than Hightown, to Lancaster), as well as where there are different train companies that price the journey you are making, depending on the destination you get your ticket for - there can be some very worthwhile cases of buying a ticket to further than you are travelling (or from before the station you are getting on), depending on the time you are travelling and whether or not you are returning the same day.
Within a fare-setting 'region' it is true that there will usually be fewer splitting 'opportunities', but sometimes they can still present themselves, e.g. if the longer fare has a wider range of permitted routes (for which you are paying a premium), vs if you reduce the number of permitted routes by splitting (and thus paying less for the privilege).