1. I was just going by what I heard and then read re: -3.5. See
http://www.nj.com/super-bowl/index...._for_denver_broncos_vs_carolina_panthers.html,
http://www.sbnation.com/nfl/2016/2/3/10904360/super-bowl-50-odds-panthers-vs-broncos-spread,
http://heavy.com/sports/2016/02/sup...-odds-total-over-under-broncos-panthers-2016/. They all mention that Carolina opened at -3.5 (-3 or -3.5 in the heavy.com link). Another site said Carolina opened at -4.5. See
http://www.cbssports.com/nfl/eye-on...ne-panthers-now-6-point-favorite-over-broncos. So I absolutely saw that number out there. Shop around or get in quicker.
I'm not the grammar police, but I hope you were being ironic when stating "your and idiot." Autocorrect is also acceptable. And of course I never said or implied that Super Bowl money is like regular game money, so the whole basis for that unprovoked attack is missing.
It's not common for a line to move 3-5 points going to/off/through a key number. No. Key number middling is death for sports books.
2. The NE/Denver line moved from NE -2.5 to NE -3.5. See
http://heavy.com/sports/2016/01/new...favored-preview-peyton-manning-and-tom-brady/. That's
through a key number, and the line moved back to 3 (because key numbers are key). See
http://profootballtalk.nbcsports.com/2016/01/24/bettors-are-lining-up-with-new-england/. Going from -2.5 to -3.5 takes a lot of money because books would have a ~15% chance of getting middled. Not so "[p]lain and simple really." Not at all.
50/50 is an ideal outcome assuming the line never moves (or moves very little), but getting there can lead to a significant risk of a middle. Start at -3.5 and take Carolina up to -7 and see an influx of Denver money might lead to 50/50 total bets each side, but not off the same spread number. If you have two brain cells to rub together you understand that there is a middle risk there where Carolina wins by 4-6 and books take a bath. In fact, late money poured in on the Broncos -6. See
http://www.vegasinsider.com/nfl/story.cfm/story/1743429 (lots of stuff in there, but here's one: "We were extremely high with Panthers action through Tuesday with 86 percent of our overall (point-spread) cash taken in on them, but that number dropped to 59 percent through Wednesday and now we're at 56 percent."). So the books have to hedge against a huge middle risk. See
http://www.wunderdog.com/line-movements.html ("A middling opportunity arises when a line moves by a large amount, and/or moves over a key number. This opportunity gives the bettor a chance to win two bets, with little risk. The sportsbooks don't like this

"). And some sports books needed the Panthers to cover, like MGM: "It's been all Broncos since yesterday -- our position has completely changed. We need the Panthers now."
http://www.vegasinsider.com/nfl/story.cfm/story/1743429.
And sports books don't just take bets on the spread. There's money line, parlays (which get pretty exotic for the Super Bowl), over/unders, teasers, etc... And Vegas has other ways to induce betting on either side of a line - the vig (which you don't mention or allude to). Those often go together with the spread. For instance, the public tends to love favorites and overs. And teasers are a way of changing the number on multiple games. A couple of weeks ago on Chad Millman's podcast (maybe the week after the conference championship games), Bob Scucci (runs Boyd gaming sports books for all of Nevada) talked about the weird situations that can occur re: parlays and teasers. He laid out that they can have > 50% on a side, have that side lose against the number (that's good for the books re: spread bets), and still suffer a net loss due to other, non point spread bets (or point spreads teased down). For example, Carolina and New England (both favorites) in a teaser won, even though NE lost against the number without the tease. He's also stated, on many occasions, that knee-jerk moves are how books get killed. And he has frequently talked about how public money came in early on the favorite, but then they got hammered near kickoff by pros (and sometimes the public) once the line swings too far. So the line moves (which occurred similarly at, what, all sports books? Almost all?) were almost certainly "per usual Vegas."
There's a lot more to running a successful sports book than just throwing out a number that might get 50/50:
"It's true that their goal
is often to split betting activity, getting about 50% of the bets on one side and 50% on the other side. This way they can't lose. They simply pay out the winners (minus their 10% juice/vig) and collect from the losers. The vig/juice on the winning bets ensures them a profit. They can't lose.
"But, the
oddsmakers' goal sometimes is to actually take lopsided action. They sometimes roll the dice,
believing the betting public will be on the wrong side and they can score a huge win.
"Despite popular belief,
bets are rarely split 50/50 on most games. There is quite often very lopsided betting. To see this in action, check out this
consensus betting tool. As you can see, there are often games in which 60%, 70% or even 80% of the action is on one side."
http://www.wunderdog.com/line-movements.html (emphasis added).
In short, throwing out
your theories on how the line should have moved, with
incomplete information (you didn't even mention changes in the vig, let alone prop and other exposure) does not prove, or even suggest, a conspiracy theory. It's not even fishy, let alone fixed:
"Surprisingly, it's not clear cut or unified who the books need." http://www.vegasinsider.com/nfl/story.cfm/story/1743429, February 7, 2016 at 2:35 PM ET (3 hours before kickoff).
So I'm going to go ahead and bow out here because I don't have the time or inclination to further educate people on how sports books work. They're much more complicated than people think, and the tinfoil hat crowd will likely never be convinced. Hope you have a good day.
Sincerely,
"and idiot"
P.S. - sorry if I sound snarky, but after living in Las Vegas for a decade and following sports betting (because they're the best at analyzing outcomes) for almost 20 years, I can't stand the conspiracy theory stuff. Yeah, a public corporation (and onshore places tend to be) is going to risk their sports book license that makes tens or hundreds of millions every year by trying to influence the Super Bowl. And they're all going to do it secretly, together or something, and nothing will leak. Just doesn't hold water. Why risk everything when you can practically print money from the public for the foreseeable future?