In plain language, what does "Backswing duration" mean on my monitor or export?

Time from address to the end of the backswing.

Units: seconds

Why does this metric matter for ball flight, dispersion, or scoring?

Sets the rhythm window for loading and transition. Sudden changes often track intent changes or transition issues.

What is a typical or competitive range for this stat?

Reference averages exist by gender in many databases; use your own historical band first.

What usually makes this number look bad or noisy in real rounds?

Very short with a rough transition can cost consistency; very long can lose coil if you idle at the top.

What other metrics should I look at together with this one?

Swing tempo (back : down), Downswing duration, Repeatability vs peers