Stafford to Rock Ferry priv return (any reasonable route?)

Hi all. I want to make the above journey but leave myself the option to decide on a whim whether to travel via Chester or Liverpool. Can I buy a ticket valid on both routes or do I have to specify which route I'm proposing to take when booking? National Rail Enquiries website just confused me!
Many thanks.

The any permitted fare is valid by both routes. However if travelling before 9am the off-peak return via Chester is unrestricted and cheaper than the any permitted anytime return.

If you're travelling before 9am, you could buy a "via Chester" ticket in the first place, and get an excess to an "any permitted" one for any leg where you decide to travel via Liverpool. I haven't tried it myself, but this is intended as a summary of the process.

Unfortunately, National Rail Enquiries doesn't show things correctly when fares on more than one route are valid on a train (such as when both "via Chester" and "any Permitted" tickets are valid). Train company sites don't share this problem, so I've never worried too much about it.

May be cheaper to split at Liverpool, especially if travelling on VT services.

Many thanks folks. When I'm back at work I'll go to the booking office to enquire. It's nice to be armed with the facts because while most of the booking clerks at my station are very helpful and knowledgeable there are one or two that can't be bothered to do anything if it doesn't come up immediately on their screen. They'll just say such and such a fare doesn't exist when you know it does!