[quote name='GUNNM']They fixed it in the next game with stat tracking.

You're sol on GOW 1 though supposedly there was a patch that wiped out kills took me a while to get mine legit just boost it.[/QUOTE]
That's what's really unnerving about it. I have somewhere between 4,000-5,000 kills (this is adding up all of my kills across Warzone, Execution and Assassination, then adding and subtracting random amounts to substitute the counted/uncounted kills when players or the host quits). I'm safer assuming it's less than 4,000, but this is from years ago. I stopped playing when Halo 3 came out, with random matches played every few months.
I'm potentially half-way there, but from all of this information about stats being reset more than once (there was apparently another update that supposedly reset player stats a second time, although players have reported that it did not affect everyone) I just can't rationalize playing through countless games to get to 10,000 kills and not have it unlock...or worse, playing even more to get a grand amount and still not unlocking it.
I was fine grinding Brumak kills to get to my 100,000 in Gears of War 2, and having matches idle to finish off Gears of War 3, but I just can't accept glitching or boosting for this achievement. If only kills in Campaign or Social Matches, or even Annex counted. Or if they had at least updated to have a setting that if people don't join your match after 5 minutes of waiting to host a lobby, 5-7 bots would be added to let you play.
I want to earn the achievement, but I can't even do that since people quit matches. It's like I have to host to ensure the host doesn't quit, while also making the matches 1 round only, hoping the other players don't quit as the match should be as short as possible with only 1 round to win.
I do recall Rod Fergusson saying in one of his streams that he and several Epic employees lacked most of the online achievements for Gears of War. If only I could somehow get the employees of Epic to have to play this game every Saturday night, so that people like myself can earn the achievement...
And I'm such an idiot that I plan to try and get Seriously and Not So Serious in Gears of War PC, just to try and have everything for the series. I just don't learn.