The Carolina Panthers opened as the favorites for Super Bowl 50 at -3.5. The spread has since fluctuated a bit and the Panthers remain the favorite, but the Denver Broncos are becoming a popular pick shortly before the big game.

Carolina, depending on the sportsbook, is between -5 and -6 and the over/under is between 44 and 45.5. According to ESPN PickCenter, the spread consensus pick is in the Pathers' favor, with 66% support from the public.

(Bovada sportsbook has the Panthers at -6 and the o/u at 45, but BetOnline.ag has Carolina at -5 and the o/u at 44.)

However, ESPN's David Purdum is reporting the initial surge of bets on the Panthers is slowly being canceled out by a "flurry" of Broncos bets. A number of sportsbooks in Vegas noted the influx of bets coming in on Denver, which is "closing the gap" on the many bets placed on the Panthers.

With Denver seemingly closing out the two-week betting window as the most popular bet, should those who have wagered on Carolina be worried?

The world's most successful sports bettor, Billy Walters, is believed to be on the late Broncos action.

"Word on the street is that it was Walters and his many associates that were scrambling at all the books to get as much +6 Broncos action as they could around town," writes Micah Roberts of VegasInsider.com. "If it were a regular season game the line would be -4.5 already with him on board, but the public's money dictates the pace for this game. A few books were relieved that money came when it did because going to -6.5 was likely to happen within the next day or two."

According to Tony Miller, the sportsbook director at the Golden Nugget in Vegas, there are a number of bets coming in for the Broncos money line as well, so the points aren't what's attracting many. Denver's money line has reached +190 on some books.

A week and a half ago, we talked about how you should go about betting this game based on trends from NFL regular season. Check out the chart below, which shows the success of both teams against the spread (as both favorites and underdogs) as well as the likelihood of the over or under occurring in those games.

*A checkmark indicates the team covered the spread; an X means they didn't cover; no symbol indicates the game was a push; and the bold next to the o/u number indicates which bet hit.

*All stats are provided by Oddsshark.com

As you can see, the most notable trends are Carolina covering the spread as a favorite and hitting the over, which has happened eight out of the team's 18 games. Carolina covering the spread and hitting the under occurred five times. In the games they didn't cover, the over covered four out of five times. On the other hand, Denver covered the spread and hit the under six times, which was the greatest likelihood of any scenario for them. In the games they lost against the spread, the over covered twice, the under covered three times, and the o/u pushed twice.

At this point, although it's not the most likely trend, I think the pick is Denver with the points and the under. The Broncos are 4-0-1 against the spread as an underdog in 2015 while the Panthers are 4-4 against the spread when they are favorites by five or more points. As for the o/u, the under covered six out of eight times for Denver when the o/u figure was 44 or higher. The over covered eight times out of 11 in the Panthers' matchups when the figure was 44 or greater.

The common denominator might be this: the Broncos won those six games outright the under covered (and covered the spread) while the Panthers won those eight games outright when the over covered (and covered the spread five times).

As we noted in our betting guide from about two weeks ago, your pick on the o/u should correlate with who you believe will win the game/cover the spread. A Carolina win correlates with the over and a Denver win correlates with the under (for any of those interested in parlays).

The bottom line is that Carolina giving five or six points is just too much for a Super Bowl matchup. In the last 20 Super Bowls, only two favorites have covered a spread that was five points or more ('98 Broncos and '06 Colts) while eight lost and two pushed. And in those games in which the underdog pushed or covered, the under covered six times against four for the over.

As a result, ESPN betting experts are leaning toward the Broncos with the points and the under.

We'd like to think those trends will have some meaning for today's game.

HNGN's Pick: Denver with the points (if the spread is still between five and six) and the under (if it remains 44 or higher)