I think we've all seen that many/most of the Type A/B free agents wait till that Golden Hour (PM Cycle Part 2 of Day 20) to sign.
There are also some Type As and Bs who sign immediately, 24 hours after Free Agency begins. There are also a few who sign later that day, or the second day. What makes those players different?
If you say it's because of something in their ratings, I'd love someone to show me that.
If you say it's because no one else was bidding for the player, I'd love someone to show me that.
I've long suspected that the easiest way to code this game would just be to give each player a specific time at which they sign the top bid. Ignore the "e-mails" you get back from the player, all they tell you is that you are or are not the top bid at that point in time. Any narrative the owners would like to make, about how the - quote unquote bidding war - went, would be entirely fiction, something you made up.
Just decide how much a player is worth to you and put it on the table. If you want to fart around with trying to see if you can beat some other guy by ten bucks at the last minute, fine. But if you really want the player, lay it down.