The QXC-Bunker - A New Way to Contain Creep in TvZ
Thu 7th Jun 2012 - 8:09pm: Starcraft II
With the recent enhancement to the Queen's range, Zergs in ZvT have been consistently opening with 4 or 5 queens, limiting the ability of a reactor-hellion opener to deny creep spread. This greatly-improved creep spread poses an enormous challenge for aggressive styles of play. The archetypal aggressive Terran, Kevin “QXC” Riley, has developed an interesting approach to delaying this creep spread.
When Mr. Bitter and Rotterdam first saw this in NASL against Shawn "Sheth" Simon, they chuckled. It seemed silly to throw a bunker downramp of Zerg's base. Then they noticed the creep spread as 5 minutes went by. More specifically, they noticed the lack of creep spread.
Compare that to the creep spread in Morrow v Targa on the same map at the same time.
While Sheth's creep spread was contained to his ramp, Targa's creep spread almost extends to the tower. That creep spread has been delayed by two full tumor's length. To a Terran, that is equivalent to roughly two seige-tank radii. This wasn’t a one-off prank either. Check out these shots from QXC's stream.
QXC clearly thinks this could be incorporated into a standard strategy. Here’s how we incorporate this bunker into good old standard generic TvZ.
The Opening Build
1: QXC does this as part of a standard gasless-FE opener against hatch-first.
2: The CC is followed up by double-gas reactor-hellions.
3: 4 hellions are made and sent to meet up with the bunker.
The Bunker Set-Up
1: QXC starts building this bunker at ingame-4:10, after the expo-CC and double-gas.
2: The first spawn of zerglings will pressure the bunker. QXC micro-managed his marines exceptionally, buying time until he could load the bunker. Be prepared to do the same.
3: Zerg may attempt a zergling runby before finishing speed. Be willing to lift your expo-CC until hellions are ready.
4: The SCV stays there to repair. You want the SCV a few squares behind the bunker so that Queens or speedlings take some extra damage trying to snipe the SCV.
5: Place the bunker such that the marines can cover the full breadth of the choke (see example bunker below - the yellow-hp SCV is within range of the bunker).
Once the Hellions join the bunker, use the hellions to manage creep spread.
2: Retreat to the bunker if the hellions are at risk.
3: Because your SCV is still by the bunker, you can repair your hellions erstwhile.
Zerg needs to break out to take a third and continue to spread creep. In most cases, this required the zerg player to make more non-drone units than he wanted. Let’s take a look at the numbers more specifically.
First, note that most zergs had to spend a lot of larva to break this bunker contain, larva that could otherwise have been spent on Drones. Second, notice that the only zerg player who broke the bunker efficiently did so with a spine crawler on Daybreak. This is the best-case scenario for zerg, and it minimally slows down Zerg's creep spread. There are 3 key things to think about regarding this scenario.
1: Clearing the bunker efficiently requires a comparable investment (in this case the marines escaped and bunker can be salvaged).
2: Zerg must invest in that Spine Crawler early (i.e. by ingame-5min).
3: An efficient break is only possible if the Spine Crawler can be positioned to outrange the bunker.
There are some clear implications of this scenario. First, if perfectly executed, the worst-case scenario for terran appears to draw even. Second, if the zerg response isn't fast enough, the creep spread will still be delayed. Third, on maps with clear primary exit ramps to the natural, this is not an option. The unbuildable space on the ramp means that a well-placed bunker will not be in range of a high-ground Spine Crawler. Let’s examine this sample bunker on Antiga Shipyard.
1: No high-ground range-7 combatant (e.g. spinecrawler) can reach this bunker.
2: The yellow-hp SCV on the ramp is within range of the bunker.
Thus, such maps are better for use of this counter-creep forward bunker, including:
1: Antiga Shipyard
3: Shakuras Plateau
4: Entombed Valley
5: Sandshorn Mists
6: Bel’shir Winter
Interestingly, because of these ramps, they are often considered safer maps for defensive play. The use of this bunker flips that dynamic on its head, facilitating stronger midgame aggression from the Terran player.
The Follow Up
Finally, now that you've kept the creep down, its time to take advantage of it. The biggest advantage to the delay of creep spread is that any push will be safer closer to Zerg's base. This advantage from the bunker will be more dramatic earlier than later, making it more worthwhile to follow up with some serious aggression. With that, may your marines safely find their way to medivacs and may your tanks rain brutal fire from the sky!