Average league fielding percentages

[BPS]

I've not seen this suggested:

Have a slider which allows you to set average league fielding percentage so that, say, you can more easily deal with early baseball in which fielding percentage was much lower than it is today.

Perhaps sliders for fielding percentage for each position and maybe for spread of fielding percentage within positions.

And to model, say, introduction of better equipment--gloves!--when you shift slider in a season all players are affected instead of fielding percentage being set, say, once for a player in a career. Or toggle that allows you to have all, or only new, players be affected by change in fielding percentage slider.