This achievement must be done online, ideally with just one other person. Once you finish a game with 1200 or more rating on the leaderboards, you will get this achievement.
This achievement must be done in Ranked matches to affect your rating.
Luckily this game starts you off at 1000 rating for your profile, this rating is stored on the servers and cannot be reset.
Now the servers on this game will take a few hours to update, but once you have been updated for the first time, you should be able to pop the online achievements as and when you earn them. When I did the online on this game, I could not pop any online achievements in the first few hours and you'll have to re-earn them when the servers update. But once they update for the first time, the achievements pop fine.
I believe it is because your rank needs to be established before you can earn any achievements and this takes a few hours.
There is an easy 2 or 3 move checkmate (3 if you're white and 2 if you're black).White to Win
White: 1. P-e4 Black: 1. P-f5
White: 2. P-d3 Black: 2. P-g5
White: 3. Q-h5 checkmate!Black to Win
White: 1. P-f4 Black: 2. P-e5
White: 2. P-g4 Black: 2. Q-h4 checkmate!
Of course you can play out the games as you wish, not in the way I described, you could even pop the following achievements while playing online.
The Sprinter achievement in Battle vs. Chess worth 22 pointsWin a game in less than 5 minutes (Classic Game, not Head to head) The Immortal achievement in Battle vs. Chess worth 43 pointsCapture 5 pieces with the same piece during a single game (Classic Game, not Head to head) The Persecutor achievement in Battle vs. Chess worth 19 pointsPlace your opponent in Check 10 times in a single game (Classic Game, not Head to head) The Sacrifice achievement in Battle vs. Chess worth 27 pointsWin a game while possessing 2 pieces less than your opponent (Classic Game, not Head to head) The Annihilator achievement in Battle vs. Chess worth 23 pointsCapture all enemy pieces and then checkmate the king (Classic Game, not Head to head) The Promoter achievement in Battle vs. Chess worth 25 pointsPromote your Pawns to every possible major piece (not Head to head) The Reckless achievement in Battle vs. Chess worth 22 pointsMove your King to the opposite side of the board (Classic Game, not Head to head) The Torturer achievement in Battle vs. Chess worth 24 pointsPlace your opponent in Check using 5 different pieces in a single game (Classic, not Head2Head) The Catcher achievement in Battle vs. Chess worth 31 pointsCapture a Pawn 'En passant' (Classic Game, not Head to head)
(it should be noted that Explorer requires Single player modes aswell, this will only cover the multiplayer side of that achievement - see my achievement solution for details)
Each game should take 1-2 mins to do because you'll have to set them up each time but the online is dead and you should find the match your boosting partner has set up by pressing Quick Match.
You're looking at about 30 matches to your rating from 1000 to 1200.
When you first start out boosting with someone else who is also an 1000 rating, you should gain around 12-13 rating per game, this will gradually decrease over time eventually dwindling to just 1-2 rating as you get near 1200 (because your boosting partner will be getting lower towards 800).
Then swap around, and let your boosting partner beat you and get them to 1200 rating, which will take a lot more games than it took for you because there is 400 rating for your opponent to gain instead of 200 which you needed.
There are also other online achievements which can be earned and will be gotten in the course of you doing Grandmaster.
Any questions, please leave a comment and I'll try and help.