You would expect there to be a lot of luck involved in defensive touchdowns, and that's the case in some respects. Picking up a fumble or an interception and having a clear path to the end zone requires some degree of good fortune. Still, some teams are also just a lot better at those kinds of plays than others.
Over the last three years, three teams have scored at least 3 more of those touchdowns than any other team. These are strictly defensive touchdowns (fumbles, interceptions, blocks); kickoff and punt return touchdowns have been removed from the equation.
Arizona has a league-best 15 defensive touchdowns over that span, and is the only team with at least 4 TDs in all three years. Kansas City and Philadelphia, with 14, tie for 2nd.
In terms of consistency, there are four other teams (besides Arizona) with at least 3 TDs in all three seasons. Three, thanks to disruptive pass rushes or opportunistic secondaries, aren't surprising: Denver, St. Louis and Seattle. The fourth (Tampa Bay) is, but head coach Lovie Smith has a long history of coaching defenses that are good at those kind of plays.
Defensive touchdowns over the last three seasons are shown below.
| DEFENSIVE TOUCHDOWNS, 2013-2015 | ||||
|---|---|---|---|---|
| Team | 2013 | 2014 | 2015 | Total |
| Arizona | 5 | 4 | 6 | 15 |
| Kansas City | 7 | 1 | 6 | 14 |
| Philadelphia | 2 | 7 | 5 | 14 |
| Denver | 3 | 3 | 5 | 11 |
| St. Louis | 5 | 3 | 3 | 11 |
| Carolina | 4 | 2 | 4 | 10 |
| Dallas | 5 | 3 | 2 | 10 |
| Houston | 1 | 6 | 3 | 10 |
| Pittsburgh | 3 | 5 | 2 | 10 |
| Seattle | 4 | 3 | 3 | 10 |
| Cincinnati | 7 | 1 | 1 | 9 |
| Cleveland | 4 | 3 | 2 | 9 |
| Indianapolis | 2 | 2 | 5 | 9 |
| Minnesota | 1 | 5 | 3 | 9 |
| New England | 3 | 4 | 2 | 9 |
| San Francisco | 5 | 3 | 1 | 9 |
| Tampa Bay | 3 | 3 | 3 | 9 |
| Atlanta | 3 | 2 | 3 | 8 |
| Buffalo | 3 | 2 | 3 | 8 |
| Green Bay | 2 | 4 | 2 | 8 |
| Jacksonville | 2 | 3 | 3 | 8 |
| Miami | 2 | 3 | 3 | 8 |
| NY Giants | 3 | 1 | 4 | 8 |
| Washington | 5 | 0 | 3 | 8 |
| Chicago | 6 | 1 | 0 | 7 |
| Oakland | 4 | 2 | 1 | 7 |
| Tennessee | 3 | 2 | 2 | 7 |
| Baltimore | 1 | 2 | 3 | 6 |
| Detroit | 2 | 2 | 2 | 6 |
| San Diego | 1 | 3 | 1 | 5 |
| New Orleans | 0 | 0 | 2 | 2 |
| NY Jets | 2 | 0 | 0 | 2 |
--Andy Richardson