To unlock the Playmaker achievement you need to immediately score a goal after receiving a pass from a midfielder. Here is my advice on how to best facilitate that.
1. Match Selection:
Choose a Game of the Week match and then tap the check mark in the top-right corner.
2. Team Selection:
Select sides. I recommend choosing the team with the better OFF (offensive) rating. Then tap the check mark in the top right corner.
3. Tweaking Settings:
On the next screen you will have the option to change Kits, Squad, Lineups, and Customize. You will need to change setups under Squad and Customize.
4. Squad Formation:
Under Squad, tap on Formation and then flick down to the bottom to select 5-4-1(2). This formation ensures that you will have the maximum number of midfielders (4), making it easier to score after receiving a decisive pass form a midfielder.
5. Offisides On:
Under Customize, ensure that the game is on beginner difficulty and that Offides is On. I don't believe you can unlock the achievement if Offsides is turned off. I tried doing it in about 15 games and it wouldn't unlock. Then I turned offsides back on and it unlocked in the next game I tried.
How to be a Playmaker
1. Getting into Position:
Know which player is the striker and which 4 are the midfielders. If you can't remember, pause the game, tap on Squad, and then check their names. When a player first receives possession of the ball in the game, their name is briefly displayed. Get the ball into the hands of a midfielder. Using touch controls, direct him towards the goal, tapping on the screen with another finger to make him sprint.
2. Making the Pass:
When you get closer to the goal, look for a teammate (preferably your striker, but it can be anyone) cutting towards the goal. If no one is making cuts toward the goal, use a two-finger swipe towards the goal to instruct your team to adopt an aggressive attack strategy, making them crash towards the goal. If a player is cutting towards the goal, tap on him and then swipe towards the goal in one motion to make him cut for a pass, and then take your finger off the screen. Next, tap on the striker again to make the midfielder pass him the ball.
3. Receiving the Pass and Shooting:
Immediately when the striker receives the pass, swipe towards to goal to have him shoot. If you dribble around first, the midfielder won't get the assist and you won't unlock this achievement. Even if you are far away from the goal, if the difficulty is set on Beginner, many shots on goal will still go in.
The achievement will unlock in real-time in the game, not after the match. So you will know exactly when you do it.