The only sudden failiure I have ever seen is the eyesocket swedged type where the salt gets in and invisibly eats the cable. For some reason, these are now the more popular style.
I have seen maybe ten rigs come down. Most from a pin coming out, but people still call them shroud failiures? (because it is less embarassing I suspect?) I have never seen a thimble type connection fail.(where the cable wraps around the thimble and is swedged back to itself. I have seen broken strands and kinked cables a-plenty.
Has anyone actually seen a thimble type cable that did not already have broken strands fail?
I have sailed in outrageous conditions with three or so strands broken, and a crew of three or so too(when I was young and foolish, on other peoples boats) so I dont truly believe in shrouds suddenly parting. The loads are more than most realize, but the strength of cable is a lot more..
I am way more concerned about the little rope on trap lines, which is more dangerous for a single handed sailor. These break all the time. New, old, green and rotten. They all break coming off a wave, or just break.
My appologies to all the sail boat suppliers for taking this tack. Hope you make up in 5/16" superdoo line what you lose in shrouds.