http://news.xbox.com/2015/11/04/halo-5-guardians-biggest-halo-launch-in-history/

"With the highest week one attach rate for a Microsoft first party title on Xbox One"

that statement basically tells us everything we need to know. According to vgchartz forza  5 launched with a 28.5% attach ratio. 28.5% of 14.5 million (would be at least a few 100k higher now, as the charts are old) is over 4.1 million. If we had new charts it would be closer to 4.5 million. So there u have it, according to Microsoft using this sites numbers guardians sold more than 4 million copies.

Wow, pretty good deduction. One of the few times I've seen predictions actually USE math. It'll definitely be somewhere around there if not more.

As soon as i read the pr, I was waiting for someone to do the math but no one did.

Given that would make Halo 5 the highest selling Halo game ever, and MS has not said this in any of it's PR, that likely means VGC numbers for Forza 5 are too high.

Also I get 29.5% so assuming Xb one is at 15 million at the time the Halo 5 launch week ends, that would make Halo 5 week 1 4.42 million, which, even taking account of Halo 4 digital sales, would absolutely make Halo 5 the highest selling Halo game, ever. 

Either someone as MS is deciding to ignore Forza 5 because Xb one had only just launched, so that game's attach rate doesn't really count, or VGC got the Forza sales very over tracked, or they got the Xb one sales very undertracked. Or VGC has the first week sales of every past main Halo game very undertracked and 4-4.4 million first week is actually still the lowest, or one of the lowest, first week sales for a main sequence Halo game.

What's going to be interesting is to see how VGC handles this information. If their raw data suggests significantly lower than 4 million then do they dismiss this attach rate information, or do they use it to bring Halo 5 sales up, or do they use it to drop Forza week 1 sales down? Or do they use it to adjust launch Xb one sales up?

Are they talking about attach rate figure right now? Forza doesn't have a 28.5 attach rate any more.

why couldn't it have sold 4 million in ur opinion. I don't get why it's out of the equation. Anyway This isn't my opinion, I just did some math. My prediction was 2.8-3.1 million (including digital). But I don't know now. 

   I doubt vgc will react at all. No one has any idea how it did digitally. Anyone saying they know is just speculation. Could it be 12% sure, could it be 40%, I doubt it but who knows. 

It seams pretty clear they are saying "week 1 attach ratio"

SLAY!!!!!!!!

It will not be near those numbers so I'm guessing VGC original figures for FM5 are a bit of.

Yeah just read it again. Seems possible. It is Halo.