Halo Gamerscore Missing Games?

What are all the games included? I added up all my achievements and they’re way off from the number on this site. I’m wondering what games aren’t counted? And why aren’t they’re not counted?

Here’s what I have done: http://i.imgur.com/FeaM04P.png
Totaling 10860 gamerscore.
Halo Gamerscore (per HaloWaypoint): 9860

That’s 1,000 gamerscore missing. So what got the cut? Halo 2 (PC)? Halo Wars? If so, why?

Why is your account has not played and is not showing the stat for Halo 3, Halo 3 ODST, Halo 2, Halo Reach online? That could be your problem why halo waypoint not giving you all your gamerscore because you need to update your account to halo waypoint. Halo 2 (PC) achievements not counted it not xbox 360 game, but a xbox game ported to (pc). I hope this help you out?

PS. Add me to your friends list and we can do some achievements for New Halo MCC for Xbox One my Gamertags is the same as my usernames.

Sorry John, I didn’t really understand any of your messages. I don’t think there’s much you can do to help me.

After further investigation / completion I figured out it’s only Halo 2 (PC) missing from this which kind of bums me out. According to TrueAchievements there’s 1,707 people that have completed this game. There’s your diehard Halo fans right there. I feel like these people should be included, if not rewarded. It’s the hardest completion of the series, minus Halo Wars.

I now have 11,300 “Halo Gamerscore” and the site only shows 10,300. What a bummer.