I've started work on writing my own pre-game editor of sorts. Rather than it being a traditional form of editor, my plan is to import and export data/changefiles between the game and Excel. The reason for taking this approach is that allows multiple people to list their research in spreadsheets and then import this into a single database (the drawback with a pre-game editor is that only one person can work on the database - this used to make keeping EHM databases updated a huge task).
I wrote a similar tool for EHM so that we could maintain our unofficial roster update more quickly and easily. The researchers can list the changes they want in a spreadsheet (e.g. transactions, attribute updates, additional career history entries, new players, etc) and then my tool applies the changes to the database. It also allows us to export data from one database and merge it into another. So this is the sort of thing I'd like to do with FHM (and it would be a way of exporting the ratings from a DB update to a start-of-season DB -
see this discussion).
Using a hex editor and a lot of trial and error, I've figured out about 85-90% of the structure of the player data (players.dat). I've found most of the bio data, all of the attributes, most of the contract data, career history/stats, draft data, etc. However, it's the remaining data that is proving really difficult to figure out. Unless I can figure out what these bits are, it's going to be really difficult to write the editor...
Even with the missing gaps, I'm able to process the first 28,903 of the 29,281 entries in players.dat (I then reach something as of yet unidentified in the DB which causes my editor to crash). I'll keep working at it every now and again, but I think we'll be very much dependent on OOTP publishing the DB structure in order for fan-made tools to be viable (e.g. figuring out what happens to the DB when you add a termination clause via Commissioner Mode is really difficult!!).
Btw, the players.dat file in the Modern Quickstart folder is the same in the structure as those in saved games - so it'd be possible to edit saved games with the same tool at present.
P.s. here's an example of one of the spreadsheets/changefiles my EHM Updater uses (and the sort of thing I'd look to be adding to my FHM version). You just list the changes like so and then the Updater will make the changes to the DB:
