It is hard to say it all in one thread...as they say a picture is worth a thousand words. If your ring is outside in a yard, you could walk around without following any particular direction. Here is a method for rods crossing over gold...this shows dowsing for a gold placer deposit.
If you walk over gold, the rods will cross. The direction of the walk wouldn't matter because gold is under your feet. Like the gold placer illustration below. Most washes don't run a true N/S or E/W direction. If they do, not for long because a dry wash will have turns and bends, plus change course often. Walking down in a wash, rods cross directly over gold approaching from any direction. It works the same way for a ring whether it is gold or silver.
Gold caches and placer gold, the rods give a parallel from opposite directions response when leaving the edge. The rods remain evenly crossed while over any part of a very large target. A small target such as a ring, the rods shift to remain crossed directly over the ring, unevenly if needed