definitely tell the difference between a circulation and proof strike. Maybe then an SMS and a proof strike would be a better comparison when trying to see the difference between 1 and 2 strikes. Even then many here may be able to tell the difference between an SMS and proof strike (without seeing the date of the coin of course). But that got me thinking... assuming that a given US proof coin (e.g. quarter) for a Mint set is struck only twice, then would a third strike make a noticeable difference on the coin? Would the marginal difference for each additional strike be noticeable? What about say, comparing 2 strikes with say 10 strikes - would there be any noticeable difference, and would it be "worth" it? I wouldn't even know what more to expect from multiple strikes after the first few or so... it's not like the reliefs would get any higher since the planchet is already molded into the incuse devices of the die, right? Would the mirrors be more... mirrored? lol I don't know maybe there are some differences you can tell from additional strikes if they're super high relief, or "super" enhanced proof designs that require "layering" via multiple strikes... but what about for your run of the mill proof coin from a Mint set? Thanks in advance!