How comfortable are you using tickets where you may need to explain them to a guard?
I always like it when this question gets asked.
The problem with the term "open" is that it used to refer to a ticket type that was valid on any train at any time without restriction and valid for a month. This ticket type is now called "Anytime Return" and isn't what you require.Just double checking the cheapest way to do an open off peak return from Wakefield to Birmingham this weekend is to do Wakefield - Derby then Derby - Birmingham?
Not applicable in this case as he's returning the day after, but you're right that is the cheapest sensible combination for this journey if it was made to return the same day and without using ticketing "loopholes"!For same day trips....