The Cowboys and Bills put up some pretty sweet rushing numbers last year – two of the 20 best running teams of the last 20 years. But it’s tough staying on top. That’s been shown time and time again.

Players get older, schemes and coaches change and opponents get smarter. And probably some scheduling as well – you benefit from an easy schedule one year, then you don’t look so hot the next year when those easy games aren’t there.

Whatever the reasons, if you look at the top 50 rushing teams of the last 20 years, only five of them came back the next year and put up even better rushing numbers. So 90 percent of these teams declined.

Collectively this group of 50 averaged 2,403 rushing yards in their big seasons, with 22.7 TD runs. Come back the next season, however, and they declined by an average of 329 yards and 7 touchdowns. The yards-per-carry also dropped, from 4.7 to 4.3.

So if you had to guess whether Buffalo and Dallas finished above or below what they did last year, the smart choice would be to take the under – definitely.

With the Bills, they’ve got a new coaching staff and a new offense. And LeSean McCoy will 29 when camp opens. I will be interested to see how he fits into that offense and gets along with the new coaches. They want him to be a more decisive, downhill-type runner – that’s their offense. But he’s never been that kind of a back.

With Dallas, they lost one of the best left guards in the league (Ronald Leary signed with Denver), and they don’t really have anyone to plug into that spot. At least not yet. Not that one left guard is going to bring down that offense, but it makes it look less likely they’ll again effortlessly mow through defenses.

On the chart below, you’re seeing the top 50 rushing teams of the last 20 years. (Plus I’ve thrown the two 2016 teams in there, tagged with black dots). The teams are ordered by how they performed in their big season (with the 2006 Chargers putting up the best rushing numbers of all). But the figures you then see aren’t their big-season numbers, but how they performed in their next season.

They’re ordered by fantasy production, using 6 points for touchdowns and 1 for every 10 yards. The five teams that improved, I’ve got them in bold.

TOP RUSHING TEAMS OF LAST 20 YEARS (the next season)
YearTeamAttYardsAvgTDPointsDiff
2007San Diego4852,0394.219241.468%
2017• BUFFALO??????
2009Carolina5252,4984.818264.179%
2005Kansas City5202,3824.626304.993%
2006Seattle4841,9234.08168.251%
2003Minnesota4932,3434.815236.476%
2004Kansas City4962,2894.631329.1105%
1999Denver4651,8644.013194.563%
2006Denver4882,1524.412206.567%
2012Carolina4622,0884.521256.584%
2006Kansas City5132,1434.217235.977%
2003Kansas City4461,9294.332312.6103%
2013Washington4532,1644.814219.373%
2003Miami4871,8173.714197.666%
2010NY Jets5342,3744.414232.478%
2007Jacksonville5222,3914.618257.487%
2008Minnesota5192,3324.515235.879%
2017 • DALLAS??????
2015Seattle5002,2684.510201.869%
2001Oakland4501,6543.714187.464%
2009Atlanta4511,8764.215207.371%
2005Atlanta5312,5464.817261.191%
2013New England4702,0654.419243.185%
2003Atlanta4351,9494.517223.878%
2004Denver5342,3334.413223.879%
2009Tennessee4992,5925.219276.098%
1997Washington4531,6153.612172.961%
2005San Diego4652,0724.522261.593%
2010Tennessee4061,7274.313185.967%
2002Pittsburgh5122,1204.115222.581%
2004Baltimore4912,0634.211194.971%
2014Philadelphia4741,9924.216220.580%
1999San Francisco4182,0955.014214.979%
2010Miami4451,6433.78150.756%
2009NY Giants4431,8374.114198.873%
2001St. Louis4162,0274.920246.791%
2001Denver4811,8773.97159.359%
2011Oakland4662,1104.516227.984%
2010Baltimore4871,8313.811180.467%
1998Pittsburgh4902,0344.28175.165%
2009Baltimore4682,2004.722269.5100%
2009New England4661,9214.119234.187%
2014Minnesota4131,8044.412184.869%
1998Detroit4411,9554.412194.272%
2004Green Bay4411,9084.39173.365%
2003Denver5432,6294.820284.3106%
1997Denver5202,3784.618256.696%
2016Buffalo4922,6305.329338.4127%
2000Washington4451,7483.914193.373%
2006Pittsburgh4691,9924.216220.583%
2010Carolina4281,8464.37157.460%
2004Philadelphia3761,6394.410162.462%

—Ian Allan