Chances are you read over the defensive strategies before this, so I won’t cover every point is so much repetitive detail. No matter which point it is, it’s always very beneficial to get one point out of the way as quickly as possible. Like I said, defence tends to flock to B, so I suggest a full (or at least half) team rush at A, perhaps with a demoman (perhaps even an übercharged demoman) being a token presence at B so as to prevent the entire defence from rerouting to A. His primary targets should be engineer buildings (especially teleport exits) rather than troops. It’s also quite effective to get up on the roof and waste the defence’s time trying to track you down (see tips, and vantage points for the best way up).
When at A or B, you need to stop the flow of defenders, not just kill the ones who are already defending. While your soldiers and heavies are busy cutting through the defensive wall, send a demoman to plug up the main defensive entrance (the big concrete door to A from C or the little door on the little door to B that’s closer to the defensive spawn) with sticky bombs to deter further defence. It may even be worth the demoman staying in preventative mode rather than joining his teammates in capturing the point, since he’s probably more use repelling resistance than as a +1 in a control point.
Control point A is an uphill slog, but there isn’t a lot the defenders can do to make the control point inaccessible. Soldiers on top of the hill will have a hard time hitting the ground around you for splash damage, and there’s plenty of cover as you proceed upwards. Soldiers should be extra attentive for the existence of sentry guns, since they are most effective at taking them down from range. Demomen are effective at clearing enemies and buildings out of the control point from below, and as always every class is more effective when the enemy team is in flames following a kamikaze pyro rush. Remember you should have an übercharge or two ready at the start – don’t use them until you need them (either right after the drop from spawn or at just about the top of the hill) and make them effective, taking out targets like sentry guns, or übering a pyro to cause extreme disruption among the troops.
As for control point B, it’s much easier to take if you can attack it from two directions (i.e. the path direct from spawn and the doors through C). Attacking through C allows soldiers to hit sentry guns from outside their range, spies to sneak in undetected, and demomen to easily plug the defensive movement (see tips). Like I said, make defenders on the roof a priority (they can’t get health back easily) and then take the roof yourself. Demomen with sticky bombs shooting down from the roof are extremely efficient at clearing out defences inside the capture zone. Similar to the defensive objective, you should be aiming to get a high concentration of troops inside the capture zone rather than to capture the point. Once it is relatively clear outside, having a demoman plug up the entrance(s) is once again a great asset to your team, and prevents a lot of interruptions to your capturing. As always, watch for spies.
Finally, attacking point C. This one can be tricky, especially if the defenders are given a few minutes to get their act together. As such it’s generally wise to attack quickly, even if only to disrupt the defence rather than to take the point. Like most maps, an übercharged demoman can be of key importance for quickly and efficiently deconstructing enemy sentry guns, and with his team following along behind, this rush can often be the best choice for even getting near the tower. Soldiers can also be very disruptive from the large concrete door into C from A, firing continuously up onto the top floor of the tower and letting the splash damage keep defenders at bay. One other tactic that can work very effectively is rocket/sticky bomb jumping straight to the top floor if undefended – see tips for more on that.
