On Sat, 1 Sep 2007 17:29:56 -0300, wrote:

Conversely, I have heard stories that leaving the mast on
during the winter may cause stress on the rigging and loosen the anchor
plates.

I assume you mean chain plates.

Probably the biggest risk is having your boat capsized off of the jack
stands or cradle by strong winds. It is not common but it does
happen. It is especially risky on dirt which is more prone to be
softened or compacted over time as opposed to concrete or blacktop.

That said, I left the mast up on my old Cal-34 for many years with no
damage at all. It is best to replace the halyards with messenger
lines to avoid wear and UV damage.