CT Strats:

The CTs, numbered 1-5, concentrate on defending the upper site, the ramp room, and, to a lesser extent, outside. Always remember that there should never be more than one CT focusing all of his attention outside, and that it is perfectly okay to concede the whole outside area as long as the sites are well-protected. The positions are as follows.

• Number One basically holds a fixed position. He should be somewhere where he can see this area, and should vary his position by a few feet or so each round. He defends against a ramp room attack, and attacks the Terrorists' flank through the hallways only if the bomb has been seen going to upper. He should save at least one flashbang for retaking upper if the site happens to be overrun by the Ts. If the Ts rush the ramp room in force and Number One has no chance to do anything useful - which would be the case if he is completely blind and Number Two has died without killing anyone, or any similar circumstance - he should retreat down the ramp and take up a position like this (1, 2), from which he should be able to kill two or more Ts.
• Number Two is also responsible for the ramp room, but has a slightly more flexible position: (1, 2, 3). Note that the last position shown is one from which the CT pops out and kills Ts; it will work best when Number Three is in his first position, and can tell Number Two when to pop out and how many enemies to expect to see. Number Two needs to be just as patient as Number One, and should move only when it is clear that the bomb is headed to upper. He should also try to save a flashbang in case site upper needs to be retaken. He should almost never retreat, though if he must it should be to the ladder room rather than to the lower bombsite.
• Number Three has a fairly flexible position that varies as the CTs identify T patterns of behavior. If the ramp room tends to come under attack fairly often, Number Three can position himself here. If the Ts are going outside a lot, he can position himself like this. Note that this position is also useful during the pistol round, where the USP needs to get headshots to be effective. Otherwise, his normal position will be somewhere on the rafters overlooking upper. He should never stand on the shed roof, which hardly slows bullets down at all, for more than a second or two. There will almost always be several Ts in the hallways, so throwing a grenade like this (1, 2) is a good idea; it will usually do quite a bit of damage, especially if the Ts are spamming. If the bomb goes to lower, Number Three should drop down into the site - if he has time and a kit, he should avoid damage by crouching and falling onto the shed - and go down to lower through the ventilation shafts.
• Number Four is responsible for the upper bombsite. He should camp either by upper entrance (1, 2), checking both outside and upper, or somewhere inside the site. If Number Three is not in the rafters, he must be inside the site. If he thinks the Ts will be coming from outside entrance, he should camp here. He should throw a grenade either at the squeaky door or into the shed if he hears Ts moving around in the hallways. He should never stand in a position where Ts firing through the door can hit him. He should also make sure never to press himself up against the shed wall face-first; see here for a demonstration of why not (1, 2, 3). Like Number Three, he should retake B by going through the ventilation shafts.
• Number Five has the most important position on the team. He is the AWPer. If the team does not have an AWP and no one can afford to buy him one, he will usually take up a position near upper entrance and watch the outside; if he sees Ts, he should probably retreat into upper after firing a few shots. If the Ts are not going outside much and Number Four can cover the outside adequately from the upper entrance, Number Five can go up to the rafters of upper with Number Three. Otherwise, he should AWP from the garage or from a position nearer CT spawn like atop these crates. From these locations, he has a huge positional advantage and should be able to single-handedly crush any T attack going outside. From the garage, he can shoot, get behind cover, and shoot again before he has to retreat toward CT spawn. From the first position, on the small box near CT spawn, he has at least three good shots, and probably four, before he has to retreat to the ladder room. If number five misses repeatedly, for whatever reason, and fails to kill the majority of the attackers, he should be sure to alert the team so that Number Four can prepare for an attack from the outside entrance. If possible he should make it to the ladder room and cover Number Three's flank.