[D] "Mech it happens", Lyyna mech thread 2.0

In this matchup, i do use the forgg 15 gas FE into hellion/starport opening sometimes, but my main one is my old WOL opening
-12 rax
-16 gas OC
-CC after second supply on high ground , cut marines at 2 if your opponent goes FE, keep producing them otherwise (might slightly delay the factory) (once my fact/port are up, i'll cut some marines to get my gas units out)
-Fact(TL asap), 2nd gas -> Port
-Go into Marine/Tank/viking, getting a raven and a banshee asap (if there is no cloak banshee, i usually go for 2 vikings -> raven -> banshee), bunker on low ground and put your CC there when you're safe, 2 gas asap
Why this build ? i wanted a build able to get a fast expand, while also having the ability to decently fight 1-1-1 play from my opponent. After some testing, i came up with this build, which has several advantages : slightly delayed 1-1-1 (30-45 sec compared to a standard 13 gas 1-1-1) and expansion (~~30 sec compared to a 1 rax FE), a tank out seconds after most marine/hellion/medivac attacks land in my base, a viking out seconds after a banshee can arrive, raven following soon, 2 scans ready at exactly 6:30 (meaning that i can double scan to fight any cloak banshees, which can come at this exact timing)

I'll not describe a lot what can happens in TvT : Mech, 111 openings, and marine/tank defense are all used in this MU, so there is a lot of pro contents about this. Main threats are :
-2 rax reaper : Pull scv, try to guess where his reapers are going to come (having your first depot near a jumpable cliff can help), trap him with your scv, and micro to death until you can get an hellion, which should be enough to stabilise if you didn't lose too much marines
-Cloaked banshee : If you can't rule out 1 base cloakshee, start to save scans around 6 mins. As soon as the first banshee hit your base, finish your first viking, get your raven and/or turrets (i usually go for the raven).
Into Marine/Tank/Banshee : Well, with my main opening, this is relatively easy to fight. Scout the lack / late 2nd base (Hellion after tank, a single marine/scv, etc.. lots of ways), Put your tanks in position, and fight ! If he's going all-in, mass repair should be enough. If he's going for the contain, constant tanks production, get your raven/banshee out, then reactor' this starport and break out of there slowly. You should have a better position, a better economy (at the very least, 1 base 2 OC, which also gives you double scan, at worst, 2 bases vs 1 + 1 building), your slightly later tech is balanced by the travel time of his units (so you should have the same amount of gas units available at your front door, and marines are basically irrelevant in this situation once you get to 2+ siegetanks)
-Marine/Hellion/Medivac : Try to win some time. Attack him while he's starting his first elevator, scare him, pull / split a few scv, and wait for your first tank, which will be enough usually to stop instantly the attack

So, you're on 2 bases, you have 4 gas mining, and you're alive. Great. At this point, it is time to get, in any order, and depending of what happened in the early game / what you scouted :
-Raven/banshee : no really, having this 2 will often save you. The early raven helps versus banshees, gives you some bonus hp with the turret, and means you'll have an easy air superiority in the midgame. The banshee allows you to exploit this air superiority
-3rd CC : i do often get it after my 1-1-1 infrastructure, before i commit to mech, in order to confuse my opponent
-2 more fact and some addon swap, in order to end up with 2 tl fact, 1 reactor fact and port
-1 or 2 armory. In TvT i like to get double uppgrade if possible, i'll get 1 if there is too much pressure/early game loss. Your ground benefits a lot of attack uppgrades versus everything, and armor versus bio, and your air will INSANELY benefit of every uppgrades (vikings/banshees attacks twice, every terran AA attacks fast/twice/4 times...)

Congratz, you have your midgame infrastructure. You should now be producing 2 hellions / hellbats (this is a matter of preference : i'll often stick to hellions all game long, but sometimes, especially if i do have some gas to spare, i'll get that transformation uppgrades and switch modes. But if you have to chose one, unless you go for medivacs, hellions are better for a defensive style, at least at this point in the game), 2 big mech units, and 2 vikings at a time. Land your third, get your 5th and 6th gas, start to position your hellions for vision, siege your tanks, get a sensor tower, and start your turret ring in your main (I do usually build 3-5 turrets at max range of each other, and if my opponent is going bio, i'll get the range uppgrade, which is basically a +1 attack for turrets, and complete the ring with 1 scv - i'll also get a second sensor tower here). Getting 1-2 thors is extremely good, they can take a lot of damage, and if your opponent is planning some kind of hidden viking(/banshee) midgame switch, these guys and your early raven will help your vikings to do the job (or if you're overwhelmed, they'll steal hold banshees, with some scv/turrets to help).

I'll usually get to 4/5 fact (1 reactor) 2 port (1 reactor) in the midgame, aiming for a composition of hellbats (filler), tanks (8+), thors (1-4, depending of how hard my opponent is yelling "IM GONNA SWITCH TO AIR SOON), ravens (1-2, except if he's for air, then i'll start to constantly produce them), banshees (no air switch, and no thors ? Well, your second starport has to work !), and vikings (If he's going to air, your reactor port should never stop working - if he isn't, make them when you have spare resources, but make sure to gradually increase your count, and keep a few ready). Get a few macro CC if you can't expand asap at your 4th, and on some maps, 1 PF and a couple tanks may be required to hold an hard-to-cover path

-Get your f**************** turret ring / range uppgrade / sensor tower in main. Seriously. Getting a bunker or a medivac with 8 of your early marines and / or a couple tanks will also help. A pure bio player WILL try to drop you, and he'll try hard. You have to make sure that any medivac trying to get through will be destroyed, and any unit landing will get bursted before there is too much : once there is too much bio units hitting with stim, you'll be forced to pull back some units (points of hellions > Hellbats.. :D) to defend. Be really careful with the minimap, be ready to focus fire with your turrets to reduce as much as possible the number of medivacs, pull scvs with autorepair for your bunker or just to distract his units, and learn to quickly judge if you have to pull some of your main forces
-Do no get into this stupid situation where you have your tanks sieged, and you pull your air force to do... stuff, and suddenly VROOOOOOOOM, 8 full medivacs comes and unload a bunch of marauders on your tanks while a bunch of men in armor charges at you using drugs. Once you have a strong position, make a few turrets, and learn to not panic with your air force : be careful with it, learn to judge his forces and yours, in order to correctly split it, but versus a bio player, NEVER leave your siege line exposed to a drop, because unlike a few banshees for example which will get distracted/killed by a single thor or turret, or will take some times to really do tons of damage, 20+ marauders unloading on your tanks while the main bio army charges will end the game in seconds. Maroderz iz gud
-For this reason and some others, you'll want to stay close to your bases (CCs) : less room for bio forces going behind your army, less possibilities for him to snipe stuff if you retreat because you won't retreat, and less time to reinforce
-Versus bio, your ultime goal in the midgame is to survive and stabilise on 3 bases. Be REALLY careful with your scouting, don't mess with your macro. Getting 5 factories helps a lot, and the second starport can be delayed (however, if he's going heavy on marauders, using your spare gas to get both banshees and ravens helps a lot). They can, should, and WILL be agressive, because they know that once you are maxed with a bunch of gas units, if they didn't trade with you, you'll be able to easily grab your 4th/5th and to push with an invincible mech army for their bioball, without enough time to get mech or air units, and with the ability to instantly remake it, thanks to your 8+ gas.
So you'll often have to max 3 bases, or at least wait until a critical mass of tanks (like, 10+), a good buffer of hellbats, and some vikings with a few ravens/banshees to help. Keep making macro CCs, and as soon as you can, move out to secure a new position when he's out of position with his main army, grab your 4th, put a sensor tower here, and aim for the lategame. Once you get your 4th, it becomes really easy to go into tank/viking/banshee/raven (i mean, with more than 1 or 2 ravens), and if you can keep your critical tank mass with 4+ ravens and a couple banshees, a bio army will never be able to break through your army.

-This can be tricky. Most of what i said about bio apply to it, because they'll obviously have medivacs and marines/marauders (A biomech player who is staying on marines for his bio force is going to get wrecked hard), and in order to look super-ultra-gosu-like-MKP, most of them will basically go "pure-bio-with-1-fact-tanks-for-lulz" : versus them, you can play like you would versus bio, and the low tank number is going to get easily cleaned up by your thors / banshees. But you'll also see some of them doing the opposite, trying to get more than 1 fact / base, aiming for a high tank count, usually one or two more ports, basically going for tank/viking with bio support, trying to get the air and tank superiority to contain you and to allow to drop everywhere. Versus that, you'll basically play like versus mech, but you'll need to have your "strong" turret ring with uppgrades, and you'll have to keep your tank lines close to your bases because there is a the risk of a bio force slipping behind your army and going full-zergling (you know, runby) in your economy, which is going to be WAY MORE ANNOYING than hellions... but, to talk about the good points, it's not going to be as scary as bio in direct engagements (tanks are not as good as marauders for this), his ability to engage easily is heavily reduced, and his army isn't as cheap. Also, his bio force is going to be a dead weight as some point if he doesn't find some occasions to trade it

-Ah, the mech mirror. Some loves it, praising its beautiful strategical play, the display of non-mechanical (ironic, no?) skills, and some.. ok, most, hates it, denouncing the lack of action, due to the fact that it's nothing but "2 big tank lines facing each other until someone's nerves cracks".
You have to be at your best here. You're playing someone who is usually going to be for a way more agressive midgame than you, in terms of composition, moves, expansions.. This can be scary. This isn't like the bio / Bio-mech match up, where you "just" get your 3 bases and then can deal with whatever happens. Especially since the armory uppgrades changes (honestly, winning the uppgrades war, especially in the air, was one of my biggest strength T_T ), you'll be facing someone with the same units, same or just slightly behind uppgrades, etc.. You have to outsmart your opponent, you have to be a step ahead, and, start to fight for gas asap. Your early banshee + raven combo is going to save you here versus 2 / 3 bases hellbat-tank(-viking) players, and it's anyway of the key here to be able to play with your air units. He's wanting to play the air war ? Your banshee will be taking a few tanks out, while your equivalent viking counts, backed up by ravens, keep his vikings busy. He's aiming for the big hellbat-tank-thor bust off 3 bases ? A million of tanks should be waiting for him, your vikings should be ready to flank and lead on his tanks, while your early banshee is waiting for your tanks to destroy his thors.
-You have to master the skills i talked about above, you have to learn how and when to cut corners or adapt to what he's doing and MAY BE DOING to do this full-air transition safely, or when it's time to forget all the subtle stuff and go full viking/thor/mine. Both players will want to optimize their gas usage, and if someone is getting 4 more tanks when both have enough to already hold their positions while the other goes for 5 banshees, already having a couple of ravens to protect versus the low thor number his opponent may make because his supply is already extremely high
-Learn to do the tank/viking leapfrog versus other tanklines. Move slowly, a tank / viking at a time, and gain the position. My style relies a lot on air dominance, why not using it as hard as possible?
-Fucking tons of macro CC to scan-spam his army. Mech vs mech is a position war, and what tool is better than scan for this?

-Complete Turret ring on your external bases
-Sensor towers + PF in every single vulnerable area. PFs can be skipped on some maps, but sensor are basically mandatory
-Spread your force, keep a few tanks siege (2-5) at each big attack patch, and put your big squads at an important movement area. Put some pdds with your sieged tanks, and turrets
-Versus bio, be really careful about air switch, with bio/mech, make sure his style (as i talked about earlier) is identified
-Keep a good hellion count to destroy drops, then mass raven/tank, a couple (litterally) banshees/thors (too easy to get picked off by marines and marauders respectively to be massed), and fill with a dozen of vikings to make sure air superiority is yours. At some point you just won't lose units once you hit enough ravens, but don't go too high (once you get 10-15 ravens, cut it, and you can start to think about BCs)

-A bit trickier, because even if he's slower than bio, his ability to take and hold a position even with a "little" (like 8 tanks with support) army while attacking elsewhere can give you a lot of troubles (assuming he's playing the lategame by going as heavy on tanks as possible in his ground army)
-You have to be way more careful with map control, because 3 tanks with a PF and 2 PDD aren't going to stop a mech army like a bio army for example. Mass CCs is extremely important, in order to scout often his position and make sure you can be sieged before him anywhere he tries a move, to avoid him being able to hit a mining base while your tanks can't approach because he sieged first
-Sacrifice all your hellions, aim for a bunch (15+) of tanks with 4-6 thors, and then aim for the biggest air army you can make : maintain a decent viking count (15 at least), a few banshees (2-6) and MASS ravens. You can't avoid all damage like vs bio when facing mech : obviously tanks don't give a fuck about pdd. You want to get enough ravens to destroy your opponent with missile spam and reduce thors / air damage as hard as possible

-Reduce your tanks number, a couple at big attack paths and half a dozen with your main ground army should be enough.
-Forget banshees (keep what you have but no more production), goes heavy on thor (hitting 8 thors is gold if you can't get air superiority from the start, they can drain pdd extremely fast, and in alternative fire mode, ignore it and/or destroy BCs kinda well) to pull his seeker missiles or BCs' fire (repaired thors can hold forever versus BCs)/ravens/vikings. Don't go too high on ravens, once you hit ~~15 ravens and 20-25 vikings consider the BC switch or more thor
At this point it is ALL about micro : splitting, running units targeted by missiles into him, and ABUSE the shit out of your own missiles/pdd

-If he's staying on ground for too long (can happens versus every start actually), a battlecruiser switch out of ~~6 ravens can be done : sacrifice your hellions and some scv, take care of drops with your air, and once you got 6+ BCs, you can attack and get his position. "Dance" with your tanks, kill his army and destroy his production (or his economy IF HE WASN'T ABLE TO MAKE A BIG BANG) before he can do anything.
-BC switch or not ? Well, BC is terrible until you can get enough support (15+ ravens and vikings) and a decent number of them (6+) (all of this assuming the opponent is correctly playing the lategame by having a high tech army heavily centered on fighting air), they're basically a perfect target for seeker missiles (the cost of it being low enough to kill BCs just with it), widow mines (too slow...) and thors (remember... TWO Yamatos) and will due to this be inefficient until your support units (or the unit itself) has a high enough count to really acquire a strong firepower dominance (a bit like the tank, in fact)
-There is two obvious ways to finish the game : be able to get to his production after winning a fight, or starving him. Both ways just ends up relying on him unable to produce. It's hard to get "economic wins" (=Your opponent knows he's too low on resources to make a comeback regardless of what happens) in TvT (and i rely a TON on that) lategame because both armies are really strong due to the scan allowing for strong counter-units play, and it's not often that you'll see close fights : usually a player will be able to end up WAYYYY ahead in a big battle with superior positionning/micro, and regardless of the economy of his opponent, he can just camp the production/destroy the tech and win (and at the very least get another position/expand and land 30 mules, replenishing his lower army deficit while his opponent is forced to use a large chunk of his bank)
-How to deny expand ? If he's not using PFs , hellions transforming into hellbats will do a lot of damage. Versus PFs, you have to chose between using your ground or your army : your ground is usually a bigger commitment in terms of position, but using your air versus a well defended PFs means you'll have to use energy on yamato/pdd, and your ground army is going to be vulnerable to an air attack while it tries to hold your positions

-Marine : Depends of your build. Your "all-around" early unit, nothing insane to say about them : you want to cut them asap (depends of your opening of course : my marine/Tank opening for example will get marines until the 2nd factory)
-Hellion : If your opening is hellion-centered, your main unit : they should be scouting your opponent, ready at his base to weakens him during the journey towards you if he attacks, ready to punish a greedy move, and at your base to defend drops. Hellions have two big strengths : mobility and splash. Use them
-Tanks : If your poening is going to them, your goal is to keep them alive. You want a tank lead in the midgame, and a couple of well positionned tanks can defend every ground attack. Usually, until you have 3, keep them unsieged in your main, near your ramp , ready to siege to defend a drop or an attack. Once you get more than 3 you can start sieging them at important locations
-Vikings : Always get one, they are ok on the ground in the early game, and will help you deal with any starport based agression
-Raven : Always get one, detector and energy-based defense
-Banshee : Always get one. Use the raven and viking to cover it, while the banshee helped to clean drops or to destroy tanks in order to deny your opponent's position

-Hellion : Your all-around unit. They'll clean drops, they'll scout the surroundings of your army, and they'll die in direct fights
-Hellbats : Hellions are better in nearly every single situation. Hellbats are mainly used if you're facing something repeteadly busting your front, trying to trade as hard as possible, or generally when you don't have to care at all about drops or unseen attacks
-Tank : Your bread and butter. Mass them, keep a couple in main if drop-heavy opponents, use them to hold position
-Thor : Emergency anti-air helper, damage buffer
-Vikings : your primary anti-air
-Ravens : support caster, point defense drone helps versus bio or air, and the missile forces some micro from your opponent.. and can win you a fight (and the game) if unnoticed
-Banshee : a couple here are really useful to exploit air superiority, punish players who are skipping anti-air, and stress him. Also useful to bait marines into your tank's fire

-Hellion / Hellbat : damage buffer and harass tool, become increasingly useless, just keep some hellions if your opponent is harassing heavy with bio
-Tank : they're here to flatten any ground army you may see, and to hold position
-Thor : Big damage buffer, pdd-drainer, helps you reduce losses by taking a tons of damage, and make sure your air army has some kind of advantages
-Viking : Primary anti-air damage dealer, must be massed in the lategame
-Raven : Primary "Let's-win-the-game" tool. Free damage, Easily avoiding damage, what else?
-BattleCruiser : Ultimate weapon when massed with the right support units, main reason i can make comebacks in TvT when not

Even with bio, there is a general consensus amongst terrans that the early game is extremely hard to play, because of the protoss possibilities, even with bio. As in WoL, i won't anyway give you one opening, everyone should try and find one which he likes
Anyway, nowadays openings with mech is basically using variations of 1-1-1 (2 fact play can work, but it's not my style, and this is about my style :D. Some people are also sometimes trying some kind of bio based opening with 2/3 rax, switching later info mech, which can work versus some people, but those who can identify that will instantly crush you with some strong timing attacks), so you should think about how you want to create your own variation
Your main early questions which are going to define your openings are
-Your gas timing ? anywhere between 11 (super fast gas first) and 16 (gas just before marine) are used , depending of what you want to do with it... nogas expands are dead with mech at the moment, mainly because you have no way to do decently with oracle play
-What units do you want ? A reaper ? How many marines? Single/Reactor mine, or even hellions ? An early tank ? Raven ? etc
-Expand timing : the 16 gas build allows you to go CC before fact, the 12 gas allows you do to so with a reaper first, 14 gas allows for a fast reactor after marine and CC after that, etc
-Overall safety : Do you want to have a blind widow mine for an unscouted oracle timing ? Do you want to be able to defend an unscouted msc/stalker poke ? Etc, etc
-Your transition : Are you aiming for the fastest armory possible for an uppgrade rush, in order to unlock some timing attacks ? Do you want to be able to do some kind of strong 2 bases contain ? To be able to get a safe fast third at the cost of your harass ? You have to plan all of this in the early game, especially because of the gas required for that

My openings currently are :
- 1-1 with 2 mines, basically copying my WoL opening getting 2 mines instead of a tank
- 1-1-1 expand with harass play, marines/ 1 mine/ 2 hellions/medivac or cloak banshee (currently the best, imho)
- 15 gas expand, 2 marines reactor CC -> 1-1-1

I always aim for a 1-1-1 infrastructure, with a fast armory. You can go for thors and tanks afterwards, i think currently the 4 thors play from my WoL's build isn't the best way anymore, going for 2 thors or even tanks asap is possible. Not sure if there is a definitive best option here.

I dont want to make the guide "how to scout and react to this and that".. Especially since 1-1-1 after expand openings had (and still has, in a moderate way) success in HotS, it's relatively easy to find resources on how to deal with a specific early game issues : even if they usually go for bio after these openings, the fact is that if sometimes bad happens early game, it'll be before you were able to diverge towards mech. I'll anyway, of course, answer any question on the subject !

Some of the things you HAVE to care about are oracles (have a way to get a turret/mine/6 marines @ 5:20 when scouting oracle !!!!!!!!!!!!!!!), MsC/Stalker/Zeal poke (impossible to defend with some gas first->super fast reactor after fact for example), blink stalkers (Even when scouted, defending some of the hardest-hitting blink play can be hard for some openings)

Oracles (before expand, 2 gas, sometimes proxied with 3rd pylon, or even 2nd pylon, but really common after expand) -> 6 marines / a mine / a turret in mineral line. Marines is annoying because if he comes with an oracle + anything, you'll die. A mine is imho the best option

Blink play (1 base -> no expand by 5:30, unusually high amount of stalkers early game, 2 bases -> High amount of stalkers, aggressive positionning on the map with his stalkers ball and his MsC) -> Retreat on 1 base until you have a good amount of tanks (once you reach 3 tanks, you have enough to hold the attack unless things goes REALLY wrong), get at least one bunker protecting your production/CC/one gas, put your tank behind the bunker, near your CC, so you can pull SCV and surround him if he tries to blink to snipe it. His goal is to pick slowly your tanks, and then abuse his mobility, but if you cant force him to lose a lot to pick your tanks, his attack won't work. For the 2 bases version, if you went for thors : switch to tanks production again, and use your first thor(s) with 10+ scv repairing to win some time

Other annoying early game play is easily fought with micro or, if you feel unsafe, a single bunker for "pressure", and allins are destroyed by marine/tank + bunkers

So, we're around 8-10 minutes, you're on two bases (with some openings, your expand might be finishing right now), having your 1-1-1 making marines/(tank/thor)/air (depends a lot of scouting and your build).
The main variation here is "do i get early cloakshees or not ?". If you do, you'll be able to force the protoss to be careful, get some probes/buildings, and sometimes win the game right now. If you don't, you'll obviously be able to have more gas for other stuff, like a raven and an early armory ( for uppgrades and/or early thors, like i was doing in WoL)

I'm not sure yet on what is the best thing, but anyway i try to have around 10 minutes :
-my armory uppgrading +1 attack if i went tanks, +1 armor if i went thors. Your second uppgrade depends mainly of his composition (zealot heavy, and you go for a lots of hellbats and starport making medivacs, or just want to be "safer" ? armor. Else, attack)
-second factory on the rax' reactor building or finished and making hellbats (Good idea to make 2 hellions first for scouting , especially if you didnt go for banshees),
-rax getting its techlab and preparing to get ghosts
-Get your 3rd CC, 3rd factory (techlab), and your ghost academy depending of scouting. If you went for thors, stop at 4, go for tanks
-Start your turret ring, get +1 range the second you start to see drops or when you bank some gas

You have a choice with your starport :
-Keeping it on techlab, allowing you to get cloak banshees, which adds a TONS of firepower to your army, and ravens, ok in a lots of different situations
-Putting a reactor (usually after 2-4 banshees and a raven), allowing you to get medivacs (make your hellbats CONSIDERABLY beefier, especially if you are facing an immortal/zeal-heavy protoss, and your ghosts, too !) and vikings (help to prevent surprise air switches)
Once you start to get resources (third saturated), you can add a second armory (optional), a second rax and port (add the addon your existing port doesn't have !), ghost cloak and start to get macro CCs

Adding infrastructures at this point won't happens that often : usually, in ultra lategame, you'll add a 3rd (sometimes, on largest maps with bunch of bases, 4th) rax with techlab, aim to have 5-8 fact (1 reactor), and a varying number of starport. Starports is the only thing you're going to really add in midgame, slowly getting up to 3 ( 1 reactor 2 TL) in normal situations, and if he's switching stargates heavily, adding 1 or 2 more (at least 1 more reactor)

Surviving during the midgame in TvP is all about scouting and being careful. While your opponent is on the ground, you can aim for the ghost/hellbat/tank/(banshee/medivac) composition, and with good positionning/sim city, easily hold most things. Always keep your hellbats in front, use your ghosts mainly on immortals/archons/HT clump, banshees focusing immortals ( DO NOT STACK THEM IF THERE IS ARCHONS / STORMS ), tanks focusing mainly EMP'd immortals, stalkers, HTs
You have to keep scouting heavily (scan production areas, make a couple hellions sometimes to check for hidden spots on the map etc...), you have a few goals with this
-Find his army, check his composition/uppgrades/etc : with experience, you'll be able to see if he's not having what he's supposed to be, and you'll be able to check in time to spot where he's using it (or if he's not using it in fact and just want to bank and hard switch)
-Find his production to be able to scan after fights and adapt !
-Find his bases

Going for mech, there is ONE opening which is better than anything : hellion/banshee. A lot of things can lead to it, your main choices are :
-CC first : obviously, the greediest and most eco-friendly one. You have to be conservative with your first hellions, and scv scout is highly advised !
-Reaper expand : there is a lot of variations of it. It is the standard in TvZ (and TvP as well) currently, giving strong scouting, and a decent economy. The main variation in the build is getting 1 or 2 reaper, and getting 2 marines after the reactor if you go for 1 reaper
-1 rax FE : the old, WoL standard. Not that good anymore, you don't have the scouting of a reaper FE, or the eco of CC first

My standard until 2014 was, since early 2012, my 16 gas expand for a faster factory (and banshee), but now i switched to Flash's version of reaper expand into mech, timings are similar to my old opening ,but instead of getting some marines, you get a reaper that allows to scout your opponent, and still 2 marines to hold your natural versus zergling pressure. The only thing i do not do like him until the 10 minutes mark is that i often do not get cloak, for slightly faster armories/Fact (on the ladder, most zergs are used to seeing cloak asap, and my multitasking is too weak to me to exploit it, so i prefer to play a bit safer, and they also go for early 2/3 bases attack a LOT, and i need my big units for this --')

Explaining early game TvZ and hellion/banshee is a bit redundant at this point, considering how standard it is since 2012. I'll just do a short summary of important stuff :
-Your first 4 hellions HAVE to be used to scouting, and you have to be careful with them. You need to know if there is 20+ speedlings heading towards your natural (and then, make sure your hellions can come back to your base and get parked in your ramp to hold), if he has an early third base, if he stopped to drone... usually, my first two hellions goes for potential third, my second set clear xel'nagas, and once i'm sure the map is cleared, i'll try to poke a bit at the natural, but unless there is an huge opening (like saturated second base with only 1 queen, no lings, and no wall), do not sacrifice them ! You go for a low number of them with this opening and need to be really careful
-Start your natural wall asap after your hellions start to scout, you'll need it if he's going for 2 bases allins. I usually do a Wol-style bunker (near CC/in a corner near ramp, surrounded with depots), matter of personal choice, delay the full wall but means your bunker can't be busted by banelings if when you have your full wall, and easier to surround with scv and repair
-Your first banshee should be sent asap towards the opponent, flying above the closest ground path between you and him. If you see anything dangerous coming (roaches --'), you have to start damaging it on the way to your base. Otherwise, just use it with your hellions to pick creep tumors, and damage/kill queens and some drones. Some zergs are really greedy, and by killing a few queens early, you can end up in a position where a zerg won't have anything but a single queen and a static spore at his third versus 3 banshees

after your first 4 hellions and banshee, get your 3rd CC and more hellions. If you didnt see anything dangerous (like no third by this timing with all gas taken), go for double armory and factories afterwards. The most modern variation of mech gets 2-4 TL starport units (usually 3 banshees or 2 banshees and 1 raven), and then the starport gives its techlab to one factory, while your starting rax makes one for the other, and the starport starts to build vikings while the rax builds a reactor (or sometimes another techlab,but currently vikings are nice to get for vipers or BLs timings).
The order/numbers of 3rd CC/2 armories/2factories is really flexile and can be adapted both to your scouting, and to your personal preference, Goody for example tends to go for a really late 3rd CC and get factories / armories before

Except if there is a massive ground army coming, your first 2 units from your TL factories should be thors, while the reactor'd one start making hellbats

Fortunately, in TvZ, there is a relatively smaller amounts of deadly things that came come and kill you. 1 base play is nearly inexistant and easy to scout (a standard reaper expo scout it in time, early pools are obviously not that hard to deal with as T.. even without a wall, you can hold these with micro), 2 bases play is kinda figured out, and with hellion/banshee, it's easy to handle most attacks your hellions can make him lose some times during his journey, destroy zerglings, and/or counter attack while he's attacking, while your banshees just destroys everything on the ground (focus baneliiiiiings !), and they can easily snowball out of control for the zerg, when you counter attack with 3-4 banshees, and sometimes killing him if he's too greedy.
Versus 2 bases tech play (often mutalisk, but sometimes can be some roaches timings - scout well, and be ready to scan ! 2 bases muta will avoid to use any gas in the early game, and you want to keep your banshees in safe place, and vs roach play, you want them near his base to keep him in good company on his way to your base :D). If you want to be extra safe, change a bit your build, go for 2 fact 1 armory, and get an ebay, but even with 2 arm 2 fact after 3rd CC, you can handle al of this as long as you scout well - and with a bit of experience, it is relatively easy to tell what is coming

So at this point, ideally, you have :
-2-4 TL starport units (banshees mainly, 1 optional raven)
-Some hellions on the map, checking bases/attack paths
-2 thors on the way, 2 tanks if you suspect some kind of roach attack
-3 factories (1 reactor 2 TL), 1 starport (TL or reactor - the TL means earlier ravens, which quite limits your gas for uppgrades/ground units, and banshees, but reactor means added safety vs muta switch, vipers, BL)