Steals and converting them into points off turnovers
This is a really interesting area to look at, because it feels like the Bucks are playing a little bit of a faster pace under Doc Rivers than they did under Adrian Griffin but that actually isn't the case as the Bucks' pace is actually down from 102.5 to 100.03. However, I believe the reason it feels like the Bucks are playing faster is because they are getting more steals and converting them quickly into points.
The Milwaukee Bucks under Adrian Griffin averaged 6.5 steals per game, under Doc Rivers the team is averaging 8.2 steals per game, and that's without Khris Middleton, who averages about a steal per game himself.
The Milwaukee Bucks are even more importantly converting those steals into points. Their points off turnovers has jumped from 13.7 points per game to 16.9 points per game! Essentially meaning the Bucks by playing better defense are able to add about three points to their scoring per game.
To be perfectly clear, the Bucks increase in points off turnovers is strictly a product of their defense as their fast break points are nearly identical (13.4 to 13.6) from before and after the change, so the Bucks defense is literally feeding their offense.