How do you know if your standing rigging is dead? There are many tiny tells that can indicate the level of health of your rigging and most of them are microscopic!
Thankfully this one tell is very small but not microscopic! (Though it is very small)
Do you see how the scum line at the base of the stay has slipped up just above the compression fitting? The scum line formed from years and years of gunk collecting the bottom of the stay at the top of the compression fitting (or swage fitting). The reason the scum line is raised is because the stay has slipped up and brought all the debris up with it!
The fact that the stay has slipped out of the fitting indicates that the fitting is failing and the stay is dead. Sailing on this rigging will lead to catastrophic failure when the stay slips out of the fitting completely!
Aside from corrosion issues, cracks, broken wires, or abrasion, which are all rather difficult to stop, this indication is rather easy to see and tells you right off that your rigging needs replacing!