If I might interpret . . . the idea (theory) is that if there are two claims within your search radius, your finder will find the closest claim to you. If the claim is VERY close to you (assuming you stood still the whole time), then a lot of the search area remains unknown. For example, if the claim is 20 meters away from you, then the unknown area (in m^2) is (55^2-20^2)*pi = 8250 m^2, which is quite a large fraction (about 87%) of the total search area. If the claim pops up right next to you, then nearly all the search area is unknown.
In my estimation for the above example, your chance to find another claim by dropping in the same spot would be about 87% of your chance of finding a claim when dropping in a random unexplored area (~25-30%). Maybe a bit more if nobody has mined there recently(?) I certainly don't find another claim "most often than not," but perhaps some people do.
In summary, dropping another probe if the claim appears close to you is nearly equivalent to dropping a probe in an un-explored area. In my estimation. And you have to stand still for the theory to hold.
Best of luck!
Noodles
