The one thing you can be sure of is that things in the NFL are always changing. It would be easy to handicap this league if teams that were strong against the spread one year stayed that way the next year. That obviously isn't the case.

Sometimes a team loses key players and they struggle as a result - both on the scoreboard and at the betting windows. Other times the teams are just as strong as they were, but the betting public is far more interested in them and the value just disappears. Or sometimes other teams just improve more from a betting perspective. Whatever the reason, this is a good time to look back at the Top 5 teams against the spread in the NFL last year to evaluate their chances of repeating that success this year:

Seattle Seahawks (11-5 ATS): It is going to be very tough for this team to continue their betting success. There is a lot working against them. Most obviously, they are the defending Super Bowl Champions. Trying to win it all again has proven very difficult for most teams in recent years, and that might not be an exception here, either.

The public was also very impressed with this team last year, and they have given every indication that that love affair won't be ending soon. Superstars like Russell Wilson and Richard Sherman will keep the team in the spotlight. They also play in a brutally-tough division, and that will make both winning and covering spreads tougher than usual.

Contrasting with that, though, there are some things working in favor of the team. Their very talented roster is largely intact, and they are built to compete again. They were far from a fluke when they won last year, so they do not need to overachieve again to win unlike some recent champions. They are well-coached and have maintained their core coaching staff despite the success. They have also had a history of betting success - last year was the second straight year in which they led the league at 11-5 ATS.

I don't expect them to be quite this strong again - they are favored to win the NFC, so the public will be heavily on them. They are not likely to be a betting disaster, though.

San Francisco 49ers (11-5 ATS): How much do you trust Colin Kaepernick to stay healthy? That's a big factor in your outlook for this team, because the backup QB situation is just a disaster. There are also some real concerns about the health of the defense - not to mention availability due to suspension. There are reasons to be nervous.

This is a very good team, though, and they will be hungry to make some waves after a couple of disappointing seasons - or at least the end to the seasons. It feels like the public is not as fond of this team as they are of Seattle. That's good news for bettors. Despite their betting success last year there is a chance for some value again this year.

Arizona Cardinals (11-5 ATS): I like this team a lot - more than some people do judging by their 40/1 odds to win it all at Bovada.

The division is obviously brutal, and Carson Palmer isn't getting any younger. The coaching is exceptional, though, and the team has been built well. Last year a lot of their betting success was the result of being better than the public thought they were - they were overlooked in the shadows of the two giants of the NFC West. That could certainly happen again, and if anything this team has improved from last year. I don't expect this team to disappoint bettors.

Denver Broncos (10-5-1 ATS): They face massive expectations, have changed a lot in the offseason, have a massive target on their backs, and their quarterback, who is more crucial to the fate of this team than any other player in the league, is far from young and a hit away from real issues. That's a lot of reasons to be nervous.

Of course, every single one of those things was also true last year. I was equally concerned, and I couldn't have been much more wrong.

Cincinnati Bengals (10-5-1 ATS): Marvin Lewis - a truly terrible coach - is still in charge. Andy Dalton now faces the immense pressure of being not just a QB who hasn't dealt with pressure when the games matter, but now a highly-paid one. The division is more competitive than it was last year.

I could go on, but the point is clear - I don't like the chances of this team repeating their betting success at all.

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