Okay, I'm home now
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. What kind of level tips are you going for? I'd suggest you learn how to boost if you don't already (ie hitting your own team with the hammer - wait until they're moving in the same direction as you and have jumped, ideally, that makes them fly farther), but I think you probably know how considering you mentioned it
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.
Defensive tips:
1) DON'T camp inside your area - it may seem like a good idea but it isn't in proper games - you've just taken yourself out of your team's passing forward play if you do
Okay, now we've got that out of the way, defending's all about positioning - use your radar. If you want to play last defender (sweeper), then you need to, first and foremost, keep an eye on the enemy attack - stay between them and your goal and you should be doing well (use your radar to see when people are boosting - often they can get over your head using this method. if they do just drop back and cover them, and let your teammates boost back to cover the other attackers). If you're positioned right you should be pushing players out of position just by being a nuisence - try to push attacks to as tight an angle on goal as possible, this makes it really hard to score.
Watch out for the cross-volleys - if you think someone's about to cross (or shoot for that matter), wait until you hear them charging, then hit them part-way into the charge (enough of a time in so that they cannot charge up fully and avoid the shake). It's often useful to get a quick hit in on a new ballcarrier - but beware of them passing away the ball quickly and riding your boost to get away from you.
As an attacking part of the team, the sweeper is involved in boosting players up into position - learn how to boost players at the right angle to get into position to recieve a pass. The sweeper is also used as a playmaker, they can recieve the ball from attackers farther up the pitch, then pass forward again - this is useful for rounding defenders or if a player's about to be killed and cannot get a shot off they make sure their team keeps posession.
Hrm... I could make all that sound a lot clearer. Time for a tutorial or two methinks
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. Hope that helps.