The New England Patriots defense helped win fantasy leagues a year ago, and that memory will no doubt help them get selected very early at the position again this year. Tread carefully.

For one thing, it's not the same defense. Kyle Van Noy, Jamie Collins, Danny Shelton, all starters or playing at least half the snaps on a regular basis last season -- those guys are gone, signing on with other teams.

For another thing, this defense was a lot better the first half of last year (when the schedule was easier) compared to the second half, including in critical fantasy areas. Sacks declined from 31 to 16, and interceptions from 19 to 6. About half as many sacks and a third as many interceptions in the last eight games, a huge decline.

Finally, recent history hasn't been kind to top fantasy defenses a year later. Of the 25 defenses that finished in the top 5 (1 point for sacks, 2 for takeaways, 6 for touchdowns), only five (20 percent) finished in the top 5 again the following season. Five more at least made it into the top 10.

Nearly half (11 of 25) didn't even make it into the top 16 a year later. So if you did nothing more than select defenses based on the previous year's top 5, you'd have a 44 percent chance of landing a below-average group.

TOP 5 FANTASY DEFENSES, 2014-PRESENT
YearTop 5 DsNext
2014Philadelphia5
2014Houston12
2014Buffalo23
2014Green Bay17
2014New England14
2015Arizona3
2015Carolina7
2015Denver5
2015Kansas City1
2015Philadelphia8
2016Kansas City12
2016Minnesota24
2016Arizona18
2016Chargers8
2016Denver18
2017Jacksonville19
2017Baltimore14
2017Rams3
2017Detroit28
2017Philadelphia29
2018Chicago23
2018Kansas City9
2018Rams6
2018Houston21
2018Miami31
2019New England?
2019Pittsburgh?
2019Tampa Bay?
2019San Francisco?
2019Baltimore?

Last year's top 5: New England, Pittsburgh, Tampa Bay, San Francisco, Baltimore. Recent history suggests one of those defenses will finish in the top 5 in 2020, one will finish in the top 10, and probably two will be below-average. So tread carefully before chasing last year's leaders.

--Andy Richardson