Basic Concept
Each season, using random.org, a basket of player-seasons will be generated. All the rookies from those seasons will be included in the draft pool. The players that get drafted will then progress through their careers until they are either dropped or retire. To keep things manageable, when we generate a basket of seasons, all seasons will end in the same digit. Hypothetically, if we start with season ending in "1", then the next basket of seasons will end in "2", then "3"....etc. That way, as players progress and new rookies are added, all player-seasons will end in the same digit. This will help make roster verification/compliance easier to manage.
Since initially it will be hard to gather enough PA/IP's....we'll start with 1885 since it is the biggest "rookie pool". I realize that in real life these players weren't all rookies, but for our purposes it doesn't matter. This allows all teams the ability to build a "base" of players at the beginning of the league. We'll randomly choose three more seasons that end in 5. After the season is over, we'll randomly choose four seasons that end in 6. Going forward, we'll always at four player-seasons at a time.
After we progress through ten seasons and thus arrive back to player-seasons ending in 5, we'll exclude the previously chosen seasons to avoid repeat players (as some of these players would still be in the league). It would probably take us around 7 calendar years to go through all the available seasons in the WIS database. If we get that far, then we can choose to begin recycling some of the previously used seasons as those players would have long since retired.