OWINGS MILLS, Md. -- The Baltimore Ravens' special teams unit was more than just the best one in 2017. The Ravens' group that is headlined by kicker Justin Tucker and punter Sam Koch ranks among the best over the past three decades.

Baltimore's special teams unit finished No. 8 in the Football Outsiders rankings that date to 1986.

Most of the Ravens' special teams value came from placekicking and kickoff returns. Tucker converted 34 of 37 field goals (91.9 percent), hitting nearly half of his kicks from beyond 40 yards. His only misses were from 46, 58 and 62 yards.

Baltimore's kickoff return team led the NFL with a 27.5-yard average, which is two yards more than any other team. This was a team effort as Bobby Rainey, Chris Moore and Michael Campanaro each combined for four returns of 35 yards or longer (including a 96-yard touchdown by Rainey).

This level of success shouldn't come as a surprise. There have been 42 teams since 1986 that have managed a special teams DVOA (Defense-adjusted Value Over Average) rating above 7 percent, and four have been recent Baltimore units (2012, 2014, 2015 and 2017). That's a credit to special teams coordinator Jerry Rosburg and specialists coach Randy Brown.

"It's not easy playing special teams here," Rosburg said, "and our guys work really hard at it."

The Football Outsiders rankings are an estimate of how many points, compared to league average, each team receives from the five elements of special teams: field goals/extra points, kickoffs, kick returns, punts and punt returns. The total is then converted into a DVOA percentage so that it can be added in to offense and defense to create total team DVOA.