2010 FIFA World Cup
44 Achievements
1000
Hold the Line
Earn a match rating of 8 or above as a Defender in Captain your Country.
5
How to unlock the Hold the Line achievement in 2010 FIFA World Cup - Definitive Guide
OlympiakosNYC
Start a new CYC with an existing player. Pick a good team and a good Defender. John Terry is fine. Play 1 game as a defender. Try to make some tackles some good passes and concede no goals and you should be a 8 with ease.
daenius
Start a new "Captain your Country" campaign and select a defender as your Pro - for instance Carles Puyol of Spain (center-back).
In your first match, try to get as many clean tackles as possible, as many pass completions as possible and keep track of your position (which is indicated by yellow pointers) and you should be good.
NOTE: Try to avoid sliding into your opponent (done so by pressing 
) as this will do you more harm than good, it's better you only press 
to tackle your opponents, since this is a much less dangerous way of going into a challenge.
If you should happen to get a yellow card (or a red one, of course) restart the game.