I too am just a novice collector of VAM
's, so please don't take this as a expert answer
Let me try a simple answer VAM
's ... are a effort to identify die marriages of all obverse/reverse die's of Morgan and peace dollars.
I am not sure how many different sets of die's were used each year. But let's say one year they used 50 different sets of die's. VAM
's are a effort to identify each of those 50 die sets. Of course you also have to add in that sometimes those die sets were swapped, one particular reverse die may get used on 2 or 3 different Obverse die.
Let me give a example .. this is not exactly how it happens .. but just a general idea how I think it works
pick a year, say 1878. VAM
1 would be the first die set that was identified for that year. When something happened to this die set, like a die crack or die clash, you would start to see VAM
Also mint employees would do work on the dies, leaving marks ...polish marks .. die gouges from tools.
For me the more marks you can find on a coin .. the easier it is to identify the VAM
. Dates and mint marks were hand stamped into the die's so they will be in different position, so they are also a good way to help identify VAM