STAT CHECK—Is defense still inside-out, or is it outside-in or corner-in?

Today I got into a really good discussion with a super basketball mind about whether or not the adage of defense being inside-out is still accurate. With the proliferation of the 3-pointer, has defense become outside in?

To get a statistical answer to this, I broke the league into three categories: The top 20%, middle 60% and bottom 20%. Then I broke it into three categories: stopping shot attempts in the restricted area, stopping shots from 3-point range overall, and stopping just corner threes. Then I looked at defending the shot (or FG%) from those same three areas.

From there I looked at the combined winning percentage of the teams in the top, middle and bottom of each section.

ATTEMPTS
The top 20% of teams  at preventing shots in the restricted area have winning percentage of 50.6%.
The middle 60% at preventing shots in restricted area have winning percentage of 51.9%.
The bottom 20% at preventing shots in restricted area have winning percentage of 44%.
The top 20% at preventing 3-point shots win at  56.2%.
The middle 60% at preventing 3-point shots win at 46.7%.
The bottom 20% at preventing 3-point shots win at 53.5%.
The top 20% at preventing corner three attempts have a winning percentage of 60%.
The middle 60% at preventing corner three attempts have a winning percentage of 49%.
The bottom 20% at preventing corner three attempts have a winning percentage of  42.2%.
MAKES 
The top 20% of teams defending the restricted area shot win at 63.3%.
The middle 60% defending the restricted area shot win at 46.6%.
The bottom 20% defending the restricted area shot win at 46.8%.
The top 20% of teams defending the 3-point shot have a winning percentage of 60%.
The middle 60% defending the 3-point shot have a winning percentage of 51%.
The bottom 20% of defending the 3-point shot have a winning percentage of  36%.
The top 20% of teams defending the corner three win at 66%.
The middle 60% of teams defending the corner three win at  47.2%.
The bottom 20% of teams defending the corner three win at 42.2%.