Can someone explain to me the rate of twist and how it relates to the barrel length?

For example: This was printed in an ad for a Lyman Great Plains rifle. "This classic muzzleloader offers such high quality features as a 32" barrel with 1 in 60" twist for patched ball and hunting loads."

I think I understand the twist rate, but wouldn't a 1 in 48" provide better accuracy? Or is that rate only available in shorter barrel lengths?