Lower pass cvr and adjusted qb traits. Cpu is so conservative by default and tight coverage really does lead to dink and dunks and more coverage sacks when they do look for the deep pass.
Just think about when most of the sacks come,
2nd and 3rd and longs
End of half, when the tend to call all streaks.
Test one thing at a time, that way you know what changed the qb play.
Maybe start w/ pass d sliders and maybe test a few games with edited qb traits.
By default M15 has improved pass d coverage, which is the cause of more sacks, and seeing how inept the cpu qb AI is. EA thinks they are balancing the game by making the qbs throw more accurate and always throwing to the 1st player that's open.
Soon as we adjust and start covering the underneath, then the sack fest starts.
It's really been an issue with Madden for years now and it's only been worse since they improved the AI coverage.