From SABR member Cyril Morong at Cybermetrics on September 21, 2016:
The [2016 Cubs] are the only team in the top 25 since 1981 (also the only team in the top 50 since 1981). This is probably due to their fielding (they lead the NL in DER with .732). Top 3 teams since 2006 in defensive efficiency rating are the 2016 Cubs .732, 2011 Rays .724, 2013 Reds .715. Cubs might be highest going even farther back but I stopped checking at 2006.
There is usually a pretty high correlation between BAbip allowed and DER for all MLB teams.
Read the full article here: http://cybermetric.blogspot.com/2016/09/cubs-have-allowed-historically-low-babip.html
Originally published: September 21, 2016. Last Updated: September 21, 2016.