Late Game Control: PvT

The problem most Terrans have in late game PvT is lack of practice in late game situations and thus most fall into an extremely bad attitude that keeps them from Improving. Bellow I'll list how to move from the early game to mid game then to late game successfully. The thing you have to remember is once you have ghost and vikings you have the stronger army until he can get out Tempest, however you are now no longer the most mobile army since you have to have your army together now, thus your style must change during the late game.
Early game: Reffer to my how to hold aggression bellow, other than that its about getting a good scout and feel for what the protoss is doing and not over committing to too much early aggression thus hurting your economy,

Mid game: The mid game kicks in around about 10min were either your 6-10min attacked never occurred, did damage, or was repelled. After that you are getting medivacs, stim and combat shield are finishes and your rounding out your Raxes. The important part in the mid game is to realize your in the drivers seat and that your the only person that can lose the game for yourself for about the next 5-10mins. Everything you do in the mid-game revolves around the protosses 3rd base, if he does not take a fast 3rd base you need to keep constant pressure outside their natural without over committing while getting up your 3rd. You do not need to drop or do any damage besides setting up a light contain with your army outside their natural while looking for opportunities to poke in and snipe key units like collossus and sentries. Most Terrans will either lose the game or cripple their economy at this point trying to force out damage to a protoss on 2 bases because they believe they cannot win in the late game which is complete bullshit.
               When the Protoss goes to take their 3rd base and has an army large enough to force you out let them take it, and start harassing. The key here is to have at least 2 points of attack the 1st at their 3rd base with the bulk of your army which is poking trying to catch the Toss's main army out of position so they can kill or cancel the 3rd. The 2nd point of attack is 1-2 Medi-vacs that are trying to drop into the main, while if you have the micro you have another medi-vac or small group that will try and poke into the natural. The trick to this is a rotation that starts with your main army and what it sees when it pokes the 3rd. If your main army sees the 3rd empty you do not need to drop the main or natural kill off the 3rd and retreat till they try to reclaim it, if your main army sees the bulk of the Toss's army fall back and now you drop the main. For advanced micro if your 1-2 medi drop in the main is met with a large enough group of stalkers try and snipe some units and pull out while moving your 3rd smaller group into the natural. Keep this up until you have crippled them enough to move in for the kill or until they have successfully saturated their 3rd and are starting to pump out enough templar to hold. Remember you don't have to drop the mineral lines you can land anywhere and pick off pylons and other structures, the goal here is to draw their army out of position so one of your other forces can move in, just don't over commit the trick is to never engage their main army with your main army while trading cost efficiently with your drops and small harassment forces.

The Late Game: The late game hits once they have established their 3rd base and have held your drops and multi-pronged harass. Just because its late game doesn't mean dropping becomes bad but it has to be done differently. Now you want to use your drops to manipulate their army movement, for instance they are moving out accross the map and your either out of position or not prepared for a fight you with a force of 2-3 medivacs try and drop or push into their natural carefully, the goal here isn't to do damage its to force them to turn around. Losing you medivacs not only doesn't accomplish this it weakens your army further so know why your dropping just don't do it blindly. The second thing you use drops for in the late game are base trade scenarios, you screwed up and took a bad engagement and now are too weak to fight his main force, this will actually win you alot of games that other wise you would have lost. The last thing is to harrass hidden expansions or expansions that are extremely far away from the main such as 5th and 6th bases on maps like Frost and Alterzheim
               The next thing you have to remember is once you have ghost and vikings in your army, your army is now much less immobile since you now need your army together to take an engagement against his main force. The thing to remember here is your army has higher dps output and is stronger than the toss's army until they can switch to a decent amount of Tempest which won't be for a good long while if at all. Ghost are very good units they can cloak, have a higher movement speed than High Templar, have better range, their auto-attacks to exceptional damage to light units, are very beefy especially with Medi-vac support, EMP does its damage instantly were storm does its damage over time, and snipe is effective against everything not just units with energy, also remember EMP removes all energy too. Besides that your bio force has the greatest dps out-put in the game and as long as you took your engagement out on the map you can out micro the Toss army which is slower.
              The key is how you utilize your late game army and were you take your engagements. You want to take your engagements in areas you can micro your army backwards and away from chokes, if the Toss army doesn't want to come out and meet you poke away at other bases and with a sinlge medivac while taking the map if he wants to sit their and let you planetary the whole map up let him it will just be along game that he loses. The next thing is how you engage Which i will lay out bellow in steps.

Late game control:
1. have your whole army on one hotkey except vikings just have them right clicked on your army to follow, have your ghost on a second hotkey, and have your vikings and a 3rd hotkey. this way you can move your army together but individually micro key groups like vikings and ghost separately.
2. When you engage have either your ghost or vikings out front depending on rather they have alot of collossus or not, if they have a large collossus count poach your vikings in and out and try to snipe down collossus before the main battle even happens, If the collossus count is low, 3 or less, poach in with your ghost, cloacked, and try to land some emps on anything that is clumped up and or snipe Templars that are out of place, prioritize emp clumps of units first as emp will remove Templars as a threat as well by draining energy. The main part here is poking back and forth with ghost and or vikings trying to weaken their army before you engage.
3. once you engage make sure your the one doing the kiting do not chase his army as the chasee usually will lose as they will be pulled threw storms or emps. Try and get some emps off on the charging zealots while Kiting backwards with your stimmed bio and medivacs while your ghost which should be separate from your army like your vikings run off towards the side. Once the front line of Zealots are burnt down charge back in bringing your ghost back into the fight now to land more emps, don't be afraid to burn their energy up emp templar if you take the storms away and lose all your energy it was worth it.
4. During this engagement the first thing you should do before kiting back is right clicking your group of vikings onto at least 2-3 collossus that way they are brought down the fastest. Then why your army is kiting backwards the Toss army either has to retreat or run their collossus through your vikings and their storms to get to your bio.
5. Never never fight with a 1-a move despite contrary belief this doesn't work for Protoss anymore than it does Terran in the late game, thats how you eat big storms or as a toss eat emps that wipe all the energy from your templar. The Protoss will have their army grouped like this, the main army in one hotkey, blink stalkers in a separate hotkey, and Templar in a 3rd. The goal of the dance is who can dance their vikings/ stalkers and ghost/ Templar the best, which since your units are faster and outrange everything except the collossus you should be fine as long as you focus done the collossus well enough with your vikings.
6. Scans never get flanked by poaching templar or the main protoss army, by the late game you should have at least 4 CCs if not more and plenty of scans make sure you use them when moving around along with have a few marines at key place like watch-towers and choke points, along with sensor towers on your side of the map.

Base Setup:
1. Turrets in every mineral line, at the entrance to your natural, and one in your production.
2. At least 2 sensor towers on your side of the map to prevent run byes and being out positioned by their main force which will result in the loss of an expansion while they recall back.
3. Having at least 4 CCs hopefully more, do not be afraid to make macro CCs which once you get over 5 you can start throwing away SCVs to grow your army and make it even stronger.
4. Having a planetary at your 4th if in a vulnerable position or far away is a good idea, also having planetaries on large maps in key choke points want to hold is also a good idea.
5. make sure to wall around mineral lines at your 3rd with a bunker and supply depot to mess up the ai of zealot run byes.

I hope this guide helped good luck and have fun.