I had an opportunity to rewatch the Pats-Saints game, to confirm my impressions. Y'all know my thesis of this post. If you want a good almost textbook example, review of what I was saying, is the third play of the game when McCourty was playing inside behind, and the Safety was there on-time, playing ahead an outside. The idea is to be positioned to intercept either balls thrown short and ball thrown too long, and to breakup passes thrown correctly to the WR, which they did.
OTOH, all is not perfect. The Saints longest completion of the night was another short long Defense, but on the right side, but the pass was literally perfect, as was the WR catch. Sometimes you win, sometimes the other guys earn their pay too.
Conversely the Chung INT was a perfect example of getting the turnover on a throw too long, with the CB, McCourty, short and inside, and the Safety, Chung, correctly positioned long and outside, for the INT.
But if you watch the game there were several such plays and the Pats secondary won most of them.