I'm not an expert Starcraft 2 player or mathematician. I'm exploring the aspects of the Protoss race as best I can and I'm hoping for some input from the TL community to improve on what I've started in each article. Rather than telling me I'm wrong, which I'm sure I am, I'd prefer it if you told me politely how things actually work as they come up. I will edit and adapt this article over time to incorporate your suggestions. I've purposely tried to avoid using numbers and figures to keep it simple but I'm open to making it more specific if you guys think that would work better.
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In this series I'm going to look in depth at the Protoss race in Starcraft 2. My reasons are selfish; I want to get better on the ladder and I just don't have solid enough mechanics to do that effectively. I have limited time in my life to play, as I have a 9 week old baby, a full time job, and a lot of other stuff to cram in to the small amount of spare time I do have so my goal is to focus on playing smart rather than just laddering a lot. I've had some success with this in the past raising up from Silver to Platinum league in 2-3 weeks by analysing my gameplay and making small adjustments Day9 style, so I have a precedent. Now I want to go deeper and look at all aspects of the Protoss race from units, abilities, timings, and build orders and more.
In this first episode I'm going to take a closer look at the humble probe, the backbone of any Protoss armada!
The Probe - An Analysis
Description
Probes are of course the worker unit of the Protoss race, the equivalent units being the drone for the Zerg, and the SCV for the Terran race. They are built at the Nexus. Their main purpose is:
* To harvest minerals and vespene gas and return them to the Nexus.
* To warp in Protoss structures. Usually this involves creating production or tech facilities within the Protoss players base, but can include offensive warp-ins such as a forward pylon for warping in gateway units, a photon cannon rush, or a proxy gateway.
They can also be used for:
* Scouting. Because of their low cost (50 minerals) they are ideal (and your only option) for early scouting of the enemy position and tech path. Probes have a sight range of 8 which is equivalent to both SCV's and drones as well as MULE's. They have a slightly lower sight range than all early military units (zealot, stalker, marine, sentry) with the exception of zerglings who have the same sight radius. As with all scoutring units, probes are often used to hold a Xel'Naga tower.
* Emergency military unit, often as a "meat shield" to allow a ranged unit (stalker, sentry, immortal, etc) to do damage to an incoming enemy force while the probes take the hits (prolonging the life of the damage dealing unit). Losing probes is bad for your economy, so this kind of tactic is usually only ever seen as a last ditch effort to defend against an attack at your base or as an all-in attack at the enemy base.
Harvesting
All basic workers (probes, drones, SCV's) carry 5 minerals per trip. The exception is the MULE which can carry 30 minerals per trip. MULES have the added advantage that they can mine a mineral patch alongside an SCV which means a Terran player can gain additional income from a saturated mineral cluster. However, only one MULE can mine an individual mineral patch at one time.
Warping In
The probe has arguably the most efficient method for creating structures. Here is a brief comparison;
* Probes create a "warp" instantaneously on the map which continues to warp in until the structure is complete. This means that the probe is only required for a split second to create a structure and can then move on to do other business. It also means a single probe can begin the creation of a very large number of structures within a short time frame. The only limitation is that apart from the nexus, and pylons, all buildings need to be placed within the radius of a pylon. In this respect, the SCV has an advantage over the probe and drone. Probes cannot warp in structures where there is creep spread.
* Drones need to "morph" themselves into a structure in order to create it. This means losing a drone and their corresponding mineral and gas collection each time a Zerg player creates a structure. This is perhaps the least efficient method of creating a building as it means sacrificing economy for every structure you create. This is offset considerably by the queen's ability to inject larvae but is worth considering. Drones need to build all structures except hatcheries on creep which is somewhat similar to probes having to build near pylons, only creep takes time to spread whereas a pylon's psi field is instantaneously there when it finishes building. On the flip side creep spread cosst energy, whereas pylon "spread" requires minerals to accomplish.
* SCV's need to be present for the duration of the construction of a structure. This means if a Terran player wants to buikld 10 barracks they need to pull 10 SCV's from the mineral line to do so, whereas the same could be accomplished (10 gateways) with a single probe. It also leaves the SCV vulnerable to harrassment as they have to actively "build" the structure and cannot fight back without stopping construction. SCV's can build anywhere on the map with enough flat tiles to do so with the exception of where creep has been spread (this includes within the radius of a pylon).
From my perspective the probe has the most effective method of constructing buildings which is balanced out by the fact that Zerg players have the capacity to create more drones than a Protoss player could create probes, all things being equal (even with chrono boost), and also helps offset the fact that MULE's are so effective at harvesting resources that it offsets the fact that SCV's have to be present to build structures. It ultimately means that more probes can remain harvesting resources more often, with only one or two probes ever being pulled to create structures at a time.
Another positive side effect of the warp-in method of construction is how quickly a single probe can begin "walling" off an area of the map. On several games I have had to or witnessed a Protoss player defensively adding structures at the base of their ramp to keep a (usually Zerg) opponent out of their base. The half-finished structures themselves are impassable and without enough DPS from the incoming units can sometimes gain hit points faster than they can be removed.
Speed
Probes have the same speed as both SCV's and drones which plays an important part in early scouting and worker harrassment. They are able to kite and avoid attacks from enemy workers. They are however slightly slower than zerglings but off creep can often make it safely back to base if they are close enough. On creep, however, the zergling gets a speed bonus and will easily catch a probe to take it down. What does this mean? Scouting with probes in a Zerg base is less effective once zerglings are on the field. It's worth noting that probes are faster than marines, zealots (not considering charge), and roaches (off creep), meaning they can be kept safe, if carefully managed, to gain map awareness in the early game. Stalkers pose a problem as they are not only faster, but their range makes them hard to avoid.
Health and Shields
When it comes to health (and shields) not all workers are the same:
* Probes (like all Protoss units) have two bars; armour/health (green) and shields (blue) with 20 points of each (for a total of 40). Shields regenerate fairly quickly out of battle and a harrassing Protoss player can abuse this, particularly against Terran players. A probe can be pulled out of a fight as the shields run out, saving the actual armour of the probe and restoring it to full health. If a probe loses armour this is permanent (without the healing abilities of an Allied unit such as a medivac).
* Drones have 40 hit points, so are equal to probes, and their entire health bar regenerates over time giving them which actually means they can take an additional hit during a battle with an opposing worker because by the time they are on low health they have regenerated enough to take one more hit. This means SCV's and drones will both beat a probe in a one on one battle (without any micro).
* SCV's have 45 hit points, giving them what appears to be an advantage in one to one combat with an enemy worker. However, their hit points to not regenerate by themselves, meaning a well-micro managed probe or drone can beat it in a fight by fleeing for long enough to regain hit points and re-engaging in battle. SCV's can repair each other which can be very effective in worker battles but costs minerals. SCV's can also be healed by medivacs which is unique in that they are both considered mechanical and biological for healing purposes.
Attack
All workers have the same rage (0.1) and attack (5). However in one on one combat a probe will lose to both an SCV and a drone for different reasons; an SCV has an addtional 5 hit points, and a drone's health regeneration is fast enough that it will be able to take an extra hit than a probe and win the battle. With this in mind it's important to carefully manage your probes in worker battles. (Thanks Jerokar).
Learning
Although each workers does things a little differently they ultimately serve the same purpose. The main benefit I can gain from this analysis is;
* Without micro a probe will lose a battle against an SCV or drone.
* Probes can be used to effectively harrass Terran opponent in the early game if carefully micro managed. They can also harrass Zerg opponents by simply getting in the way of hatchery placement, but are at additional risk due to the early appearance of zerglings.
* Probes warp in structures quickly for a reason, they need to be harvesting resources, not held up building things. The balance of the game requires keeping your probes in the mineral line as much as possible. I'm not going in to chrono-boost at all here, that's another article.
Questions
* What is the actual mineral benefit of a good worker split?
* Is it worth trying to rally probes in line with close mineral clusters?