I went a little bit further because the IDP dynamic just plain interests me. I built a tester league over at Fleaflicker and plugged in your formula then took a bunch of screenshots. Then I changed the scoring to something more standard: tackles/1, assists/.5, sacks/INTs/FF/3, PD/2, and took pictures of that. Here are a couple quick snapshots:
As you can see, there is some adjustment but I don't believe it is as severe as most people assume. Your special play makers do indeed move up, but points are also added to those all around IDP (okay, mainly LBs) who play well
. On top of that, you can see the point differences tier a bit sharper in the higher point league. Whereas there is only a ~30 point difference in the standard league, from top to bottom, there is a ~70 point difference in the other. There is not much you can do to curb that in your draft, as special plays are quite random, but you can draft players who you believe are in good position to make plays.
20 IDP is a very deep IDP league, so you'll be drafting some of your guys on blind faith. One thing that I tried which worked out was to draft decent DBs (third year-ish) opposite of shutdown/elite DBs because they will be thrown toward a lot so they will have plenty of opportunity to net plays. another thing you could do is draft more than one player from teams which blitz alot, or players with schedules against several weak o-lines.
The rest of the images I took can be found HERE
. Sorry, I only grabbed the first screen of each category but there are lists of the top tacklers/sacks/DBs/LBs/DLs from each point setup. I didn't bother with INTs and other plays because they don't occur often enough imo to warrant the snapshot. Also, Fleaflicker gives points for, but doesn't include in the stat graph (obviously), passes defended