[BR/D] PvT Aztec (SWL Spoilers!)

Opening Analysis:
This is a game between Bisu and Flash, on the map Aztec.
The interesting aspect of this map is that the main is on lower ground to the nat. This feature makes it difficult to break out if the opponent is able to contain from the high ground at the entrance. Simply imagine yourself in the lower ground with an FD or dragoons and your opponent has dragoons or an FD in the higher ground. A lack of vision and a 30% miss rate makes it difficult to fight upwards. The map is quite similar to Reverse Temple and Neo Requiem (except for a larger distance) which are maps that favor early pressure. Hence, it is quite normal of Bisu to build the gateway at the nat despite the vulnerability of it being attacked and also for Flash to opt for some above ground build.


Bisu begins with building his gateway at his nat. The placement of the pylon and gateway has actually a few things to it. The usual reason for the gateway to be placed in the front of the nat is to assist in walling should a vulture runby come later and also to reach the opponent quickly for his zealot strategy. The pylon's placement also has an importance. At first glance, it would have made more sense to put the pylon at the top of the gateway to assist the wall-in, leaving only a small space for units to get through. However, by doing that, it becomes more vulnerable to bunker rush and it would be harder to defend.

A bunker rush is not completely unlikely due to the incentive for early pressure for a contain based on the map. Although the map is big, if Flash did a successful early attack through a proxy rax and by bringing scvs, Flash could easily build a bunker at the top of the ramp that would be difficult to break. This is a definite possibility as there has been quite a history of Flash cheesing Bisu (e.g. Hitchhiker, Monty Hall), and also because the map is quite difficult to TvP, Flash may want to end it early. Hence, the pylon was probably built there from this possibility.


The scouting probe arrives when Flash is building the barracks. Based on the position of the barracks and the percentage complete, Bisu has more assurance Flash is not doing a cheese. It harasses the scv a little bit before moving into Flash's main when Flash sends scv to defend.


The probe scouting the main confirms Flash is not cheesing, this can be done by looking at the scv count. The probe going near Flash's gas causes Flash to take his gas in response. This move actually slowed down Flash's FE quite a bit, but it was needed in case Bisu steals his gas. Recall that Flash lost a game to Stork on Bloody Ridge due to gas steals, and this map also favors the early goon pressure should Bisu choose such a strategy.


Flash's scv goes the wrong way and misses the incoming zealot. All that can be said is luck is entirely in Bisu's favor.


Bisu's zealot arrives when Flash is building his 2nd marine. His first marine is busy trying to kill the probe in the main.This allows Bisu to walk around the wall freely without taking damage. An important note here is that the depot at the nat is Flash's second depot. Flash is already slowed down from the gas before cc build, and flash would have to cut scvs a bit earlier to squeeze out that marine due to the lack of minerals and also supply cap.


The depot is necessary for the supply and Flash would have built it anyway rather than a bunker if he saw the zealot. He could have built a bunker after, but remember he is low on minerals. Also, placing a bunker is difficult as his units may be in the way and Bisu would try to block it. Putting the bunker left of the depot above the barracks is only a temporary solution. It takes time to complete and Bisu's current zealots could just run in main (unless Flash could block it in time). It also leaves the left side vulnerable to dragoon harass should they come, as Flash have yet to scout Bisu. The fact that a zealot came one at a time means it is not dual gate, which means Bisu could be using his resources to tech. Putting a bunker on the right side would just allow zealots to run pass.


The situation at Flash's base is just a micro battle where Bisu tries to kill scvs/marines while Flash defends utilizing his wall by running marines through them. This picture here is just to highlight the minimap to show Flash did scout Bisu. The camera does not show it but the scv is killed by a zealot without even making it to see the forward gateway. This actually doesn't have that big of an impact except not being able to scout if Bisu is expanding or teching. Based on Bisu's zealots and the map, Flash could have probably already guessed it's a forward gateway.


Flash later builds bunker quite soon right after starting his factory before even any dragoon has arrived. This bunker is not to counter zealots, as zealots could just run past and it is difficult to wall with scvs based on the large gaps. The timing is for dragoons. It is not necessary a miscalculation although it was built way before a dragoon even came, only because Bisu expanded first. If Bisu had chosen to tech to goons without FE to try and end the game, the bunker is more or less right timing. This bunker prevents goon from walking by, because if it passes through, the scvs will wall off the goon above the gas area so it will take hits from the bunker without able to pass through. By preventing a dragoon to pass, Flash was able to make a vulture before his machine shop to take care of the zealots in base.

Conclusion
Flash was put into a disadvantage due a few cases of bad luck: Bisu was able to scout Flash first causing Flash to slow down his build and also Flash scouting wrong. The micro battles also put Flash behind. Bisu played this advantage out by expanding rather than teching quickly to end the game.

Flash's Alternative
Looking back at the game, I think the best thing Flash could have done is build a temporary depot at the location in this image. Although minerals is scarce and Flash does not know if a continuous stream of zealots is coming, if he had known and had the resources building it here would be much better than placing a bunker to fend off the zealots. The depot here is zealot proof, it cannot be placed any lower because zealots can walk pass the right side of the gas. The depot does not need to be complete and can be cancelled later if needed. It may or may not have worked but I think this would have been the best solution.



I've read some people said Flash was unprepared for this game by being sent out this early. While this is true to a certain extent, Flash's building placement was definitely well suited for the map. However, I can't say whether it's simply because he knows this map or he specifically prepared for it.

I hope my analysis is insightful and clarifies on things of why the players did certain things. I wished to have posted this sooner when it was more relevant but I had my exams this past week. Feel free to discuss whether my insights are correct or wrong, and if I am missing anything important.