Have a look at the map* in this link:
https://en.wikipedia.org/wiki/Ordsall_Chord
Before the chord was built, the only way to reach Victoria was to go out to Salford Crescent (towards Bolton) and reverse there to reach Victoria via Salford Central.
But that route was very rarely taken, and generally TPE services went out from Piccadilly to Stalybridge via Guide Bridge and then to Leeds via Huddersfield.
The Calder Valley route from Victoria via Todmorden and Brighouse is a diversion route used when there is engineering work on the Huddersfield route.
* Having had a look at the map, it's rubbish.
It tries to describe the full Manchester Hub upgrade, but in fact only the Ordsall Chord was built (described on the map as Castlefield Curve).
The captions on the lines heading east and west are wrong too.
But it does give the idea of the Chord's route.