Although Protoss have received the most drastic changes, Terran appear to be the most discussed race since patch 4.0. One interesting trend is the prevalence of mech in the three match ups.
Just to clarify for new players. Bio is the most popular compositions through out the Starcraft II history. Marine and Medivac are the core of the army, and other support units (e.g., Siege Tank, Marauder, Widow Mine) are added into the mix based on opponent’s army choice. While the definition of mech has been debated over the years, it can largely be considered a composition that focuses on Factory units. Siege Tank is often the core of the army. Mech was largely considered most viable in TvT, moderately viable in TvZ, and least viable in TvP in Wings of Liberty and Heart of the Swarm.
There are two less discussed macro trends about mech. The first one is how the development timeline seems to always work against mech. Mech usually takes some time to get figured out whenever there is a shift in meta. However, ironically, massive changes were often implemented whenever mech was making a splash in the pro scene. For example, turtle mech had a huge success in TvZ at the end of Heart of the Swarm, but the switch to Legacy of the Void came timely to reset everything. The second one is how hard Blizzard have been trying to have both bio and mech viable for Terran. While the intention is admirable, I am largely skeptical of the unintended negative implications which could result in a net nerf to Terran.
The current popularity of mech could be traced to these two trends but in a rather strange manner.
Terran versus Terran
TvT is the least affected match up of the three by patch 4.0. The mech related changes are not enough to make mech more playable than before against bio. Cyclone’s anti-air buff is negligible. Widow Mine nerf does not really matter. Smart servo is unlikely to make a difference. Raven’s redesign does not exactly improve mech, and Vikings and Liberators are definitely better air options for mech in TvT. With that being said, I think mech is a viable option, and maps have a strong influence on its popularity.
Terran versus Zerg
INnoVation and TY were using bio and mech interchangeably against Zerg in WCS Global Finals and GSL before patch 4.0 (see vods below).
However, right now, mech is more used than bio. This trend is moving in the opposite direction of the first macro trend I mentioned earlier, as it would have predicted that mech would take a back seat whenever a major patch hits. In my opinion, it is less of the rise of mech but more of the fall of bio. Many have attributed the decrease in popularity of bio to the Zerg composition shift to Zergling, Baneling, and Hydralisk, for example, TLO was suggesting ZBH is too effective against bio (see vod below).
While that is not wrong, the real underlying issue is the potential of bio in the mid game. ZBH is considered effective, because it is the best answer against bio attacks in mid game. Then, how does this result in the rise of mech? Broadly speaking, Terran have two strategic options in mid game TvZ. You either get a second Factory for a mid game Siege Tank heavy composition or tech early to the late game composition with mass Liberators. The former is considered the more orthodox option, but it is basically cancelled out by ZBH. In contrast, the latter acknowledges the ineffectiveness of a Siege Tank heavy mid game, and only uses bio and Widow Mine to bridge the transition to a late game army (see vod below). Then, since the game plan is to get a late game army, why not simply go for mech which has a better late game potential?
To further make mech an obvious choice, Terran now have very limited effective early game aggressive options. When I say early game options, I refer to macro-oriented attacking choices like a Widow Mine drop, so extreme cheese builds do not count. Previously, there were 2-1-1, Hellion + Banshee, Hellion + Liberator, Widow Mine drop, and Hellbat attacks. However, most of these options slowly die out as Queens are very effective for early game defence, and the anti-air attack range buff might have just tilted the scale too much. Hellbat attack is the only one used in the recent WCS Global Finals, and I think this is mainly due to its relatively low reliance on air unit support. As a result of not being able to benefit from attacking in the early and mid game with bio, mech becomes a clear choice.
Other recent changes like Widow Mine’s nerf and Raven’s redesign have also pushed bio away. Widow Mine’s nerf is self-explanatory. Raven’s Auto Turrets were effective against ZBH in the mid game, because Zerg do not have air units to kill off the Ravens hiding at the edge of the map (read the TvZ part). The removal of Auto Turret does not only limit Terran’s early game build options, it also decreases an important factor that help Terran out-multitask Zerg. This is linked to the second macro trend I mentioned earlier. Taken together, it is not a surprise that mech is the mainstream option for TvZ now.
Terran versus Protoss
I am going to start by saying Protoss are favored in the match up. Despite the most recent balance changes nerf Protoss (especially Oracle), there are still quite a number of unresolved issues. I know people have pointed out many different problems with the match up, and I think they all converge to the one thing that Terran do not trade well with Protoss. Stalkers’ stats and Shield Battery obviously have direct effect on how the two sides trade in a battle. Chronoboost ensures Protoss are always ahead in upgrades. All these have a negative impact on the usual mid game bio power spike.
But is mech better than bio? In my opinion, no. Protoss have good anti-mech units like Immortal and Carriers, and there are various mid and late game options against mech. The recent changes to mech are not enough to overturn the longstanding problem of mech in TvP. When you combine the history of TvP and the first macro trend I mentioned earlier, it is very surprising to see mech being the main option now.
INnoVation, TY, and other top Korean Terran have been using mech on stream recently. This is usually how it plays out.
- A Reaper expand into Reactor Cyclone.
- Transition into three Factories (2 Tech Labs and 1 Reactor) with three Command Centres.
- Attack with Cyclones and Tanks (mix in some Hellions).
- Stop Tank production and focus on Hellbat and Cyclone. Transition to sky Terran.
The Cyclone anti-air buff helps to deal with Oracle, and other aspect of Terran mech largely remains the same. The Cyclone and Tank push is good against a Stalker heavy army, but it is weak once Immortal and Achron become the main army. There are just so many ways Protoss can deal with mech. I must say I enjoy watching INnoVation laughing at himself when he got destroyed for using mass Widow Mine against Carriers. He also had lost to other more interesting approaches. Overall, it seems like the pros have given up on bio in TvP, but mech is not any better. TY went even further to use sky Terran in TvP (not as a transition). In case you think he is trolling around, he had actually pioneered sky Terran in TvZ in 2016. It did not work out well.
They are desperate.
All in all, mech is not uprising, but players are desperate for an alternative to bio. That is another way of saying bio is in a bad place now.
We know Blizzard want mech to be more viable than it was. In a way, they have succeeded (yeah!). I am sure they are keeping a close look at the current situation, but I think they are unsure what changes are good for the current situation. I look forward to their next community update.