It appears more than DRS is needed if we are to see more overtaking in F1. This year there were about 1/2 the number compared to last year 435 V's 866. At Sochi there there was only 1 recorded in the whole race which was the lowest number of passes in the season.
Daniel Ricciardo was the best overtaker with 43 in total along with Verstappen's 22 makes Red Bull the best team.
The most passes on the first lap over the season 36 by......... Lance Stroll!
http://classic.autosport.com/news/report.php/id/133451