To contain the opponent, allowing attacker to expand freely. Try to siege tanks so that ramp is in range to stifle attempts at reinforcement. If opponent has walled off, siege in tanks of his buildings to be able to snipe of depots and addons.
Once a contain has been set up, the attacker is free to expand and take complete map control. Users can continue to rally to the front, adding Vikings to gain tank range, and also buildings turrets to limit the range of defenders Vikings. This opening transitions well into Marine/Tank/Viking
4 rax marine still leaves room to expand, whereas 5-6 rax is very all in and is aimed at killing the opponent immediately. If doing a high econ mass marine, once you expand, throw up 4 refineries and tech to your chosen composition.
The idea is to fast expand whilst putting on pressure. Take no gas at the start. After your first 2 rax build a 2nd cc. You can then add a 3rd rax and constantly produce marines and workers. When once you can afford it throw down 1 gas, followed by a factory and tech up to tanks and medivaces.
To delay and punish zerg fast expand, whilst expanding yourself. Also forces zerg to make lings instead of drones, giving you an economic advantage. Allows for a stronger mid game push. Ideal targets are queens and overlords. If you can snipe the natural expansion that is a bonus.
You can either hit with 3 marines to try and catch your opponent off gaurd, or wait for 5-7 marines, though waiting this long can make the rush much less effective unless the zerg is droning super hard. Only do this build if you see the zerg fast expanding. If they haven't expanded by 4:30 they will be teching and you should abort the rush and build a bunker or 2 at your front. The attack is more effective, the closer you build your bunker to the hatchery, so building it before the hatchery is finished is ideal as the creep spread will block your bunker from being put down within range of the hatchery very quickly. Not only will building it closer allow you to shoot the hatchery directly from the bunker, it also decreases the area that zerg has to build a spine crawler allowing you to possibly snipe it from inside the bunker. This being said you'll also want to build the bunker just outside of the vision range of the hatchery, or any overlords or the zerg will pull drones to delay or even force a cancel on the bunker. You will want to keep your scouting worker alive for as long as possible, not only to build the bunker but to repair it as it is being attacked.
Scouting it early is essential. Keep an overlord just in front of the hatchery to scout for any lingering scv's or bunkers being put down. If you do scout it early, pull 5-6 drones and try to focus down the scv building. If a marine shows up by itself it's also possible to surround and kill it for minimal losses. If you hadn't scouted it, build a spine crawler and uses you queens transfuse efficiently to pick it off from a distance. The spine crawler has a longer range than the bunker so this is the most effective way to destory a bunker. Keep zerglings nearby and try to get a surround on any marines that get greedy and leave the bunker. It's a bad idea to attack the bunkers heard on after they are full as 4 marines and a repairing scv is more than enough to fend off 10's of lings. It can also be a good idea to send a few lings to the middle of the map to cut off any reinforcements, and also flank any retreating marines once the attack is finished.
You'll want to get an observer spying on the Terran tech path and find the optimal time to attack. If no bunkers have been constructed force your way up the ramp, leading with zealots. Use your observer to get sight of the high ground and snipe important units, structres with your stalkers and immortal. If the opponent fast expanded, use your sentries to block the ramp to suffocate reinforcements.
Scouting early is important.You'll need 2 bunkers ideally at the front of your base, and hotkey 5-6 workers to be ready to repair bunkers. Snipe the Immortal and then clean up the rest, Stim and Concussive Shell are super important to defend this push.
Protoss' 2nd gas will go down after their 2nd gate, and you should be able to keep your SCV alive long enough to scout the robotics facility being planted. Try to keep it there long enough to see it finish to make sure they don't switch tech path, though this is rare.
As I'm sure you clever folks have noticed, it's far from finished. This will be a work in progress and over the next few weeks I'll be pouring through a million and 1 replays looking for the most common timing attacks and learning all their ins and outs. I also intend to add the replays of the best examples.
I'm a Terran player so I'm unfamiliar with the other matchups, aside from what I see on GSL, NASL, IPL, TSL etc.
I'm doing this to improve my learning, and also to help out people at a similar stage as myself, where are mechanics are starting to solidify, and it's time to move onto something a bit meatier.
Please feel free to make suggestions, whether that be adding different timing attacks, or removing ones that aren't that common. Also If I've written something that's just complete nonsense, feel free to let me know by commenting or PM'ing me :D
What I'm looking to do is not only have the timings, but also the units to expect at those times, what you need to do to execute this timing, and also as the defender, what you need to do to scout and hold the timing attack off.