Oh, we started doing these lists again
Here are two of the main tweaks, imho:
- Substitutions: this has always been the main shortcoming of SP game engine. This could be solved by a simple logic (it does not mean a simple implementation): the current performance of a player can be seen as an average value over the 90 minutes, starting from a max at the beginning of the game, and going down to a min in the 90th minute. This means that, if the player only plays for 45 minutes, his performance would get better. This way, substitutions would actually make sense and they could improve the lines ratings. Each manager could schedule, for a given game, up to X substitutions, with the minute they want the subs to come in. Of course, if a player is injured or GK sent off, the current automatic system would replace one of the scheduled substitutions.
- Transfers: this joins Andrei's comment above regarding the transfer market. Too many managers are playing SP with a sell and buy approach. One way to address this problem is to adjust the wages the players ask with the number of transfers the team making an offer has. Do you want to do 50 buys and 50 sells every season? Ok, but the players would ask much higher wages from you than from someone who does 5 transfers per season.
And +1 for Andrei's idea with the randomly defined peak period per player. I would love to have 18 years old or 36 years old in my first team.