Strength of schedule numbers are tossed about in the preseason, but teams change. Some will be a lot better, while others will be worse. So teams with seemingly difficult schedules often wind up playing only modestly hard slates.

The Lions, Saints, Rams and Panthers. Those are the four teams that project to play the hardest schedules in the league.

But that doesn't mean they will. In fact, they probably won't.

Teams change. That's the reality in the NFL. So when trying to attach strength-of-schedule numbers to a franchise, keep in mind that you're shooting at a moving target.

Since the league went to a 32-team format in 2002, for example, look at the 41 teams that have entered the season projecting to play the easiest schedules. These are all teams whose opponents had combined for win-loss records of at least 138-118 -- 20 games over .500.

But look at how those schedules actually finished. Of those 41 teams, only 7-9 played what I would call a really tough schedule. About a fifth. And 10 of those hard-schedule teams played opponents that didn't even go over .500.

The 2005 Dolphins and Super Bowl Saints of 2009 lead the way. The Saints were supposed to have a hard schedule that year, but instead their 16 opponents went a combined 106-134. (They actually went only 109-147 overall, but for the purposes of this study, we're leaving those 16 New Orleans games out -- we want to see how they did against the opponents, without factoring in whether the Saints were any good themselves.).

The majority of these supposed hard-schedule teams played schedules that were harder than average but not particularly difficult.

So for this team, my guess is that of those four tough-schedule teams -- Lions, Saints, Rams, Panthers -- one will actually play a truly hard schedule. The other three probably will play pretty typical schedules.

And this works the same way at the other end, with the easy-schedule teams.

Hardest schedules, 2002-12
YearWLTPct
2002San Francisco1231170.513
2002St. Louis1211190.504
2002Seattle1201191.502
2003NY Jets1251150.521
2003Tampa Bay1211190.504
2003Philadelphia1181220.492
2003Dallas1121280.467
2005San Diego1361040.567
2005New England1241160.517
2005Miami1101300.458
2006Cincinnati1291110.538
2006Tampa Bay1251150.521
2006NY Giants1251150.521
2006New Orleans1121280.467
2007Buffalo1231170.513
2007Oakland1201200.500
2008Cleveland1331043.560
2008Pittsburgh1291083.544
2008Cincinnati1301100.542
2008Baltimore1271103.535
2008Detroit1271130.529
2008Jacksonville1261131.527
2008Houston1241151.519
2008Indianapolis1231161.515
2008Minnesota1231170.513
2008Tennessee1141251.477
2009Miami1341060.558
2009Carolina1301100.542
2009Tampa Bay1291110.538
2009New England1261140.525
2009NY Jets1251150.521
2009Buffalo1221180.508
2009Atlanta1221180.508
2009New Orleans1061340.442
2010Cincinnati1371030.571
2010Houston1241160.517
2010Dallas1211190.504
2010Tennessee1201200.500
2011Carolina1191210.496
2012NY Giants1261131.527
2012Denver1141260.475

--Ian Allan