This is a study & analysis of the efficiency of cannons and their use by SW)LittleAngel

Some newbie protoss start with 1 gate then forge, here is some analysis about this cannons issue I did some experiment about this cannnons issue. Here are the result:

• One pylon and one cannon (150+100), can be killed by two zealots (200).
• One pylon and two cannons (300+100), can be killed by three zealots (300).
• One pylon and three cannons (450+100), can be killed by five zealots (500).
• One pylon and one cannon (150+100), can be killed by two dragoons (350).
• One pylon and two cannons (300+100), can be killed by three dragoons (525).
• One pylon and three cannons (450+100), can be killed by four dragoons (700).
• One pylon and 10 cannons(1500+100), can be killed by 18 zealots (1800).

Inspired by BrattTsunami's website and his calculation, I tried to calculate the efficience too. (too complicated for me, so I need to ask my brother, but finnaly I got the idea)

Unit	Defence(hp+shield)	Cool Down (cd)	Damage (dm)	Cost (co)	Attack=dm/cd	Cost/attack	Cost/defence
Dragoon	180	30	20	125+50	0.67	262	0.97
Zealot	160	22	16	100	0.73	137	0.63
cannon	200	22	20	150	0.91	164	0.75

So the most effiecient unit for ground attack is zealot, which also most effiecient defensive unit (vs ground attack). However that calculation does not consider the advantage of range, which has been confirmed by experiment above (e.g. 18 zealots > 10 cannons and 17 zealots = 10 cannons), which make cannons are more cost effective, since cannons have range advantage. However combination of 3 zealots + 8 Goons would be better than 10 Goons. Since goons only do half damage against zealots (since it is small), so we can use zealots to absorb damage, I tried this matchup, mix unit won.

Back to cannon farmers issue, one canon about same strong as two zealot, and one canon about same strong as one dragoon. TOn average cannons are more cost efficient than dragoons or zealots. Goon range upgrade (from 4 to 6) might improve goons chance too, since cannon range is 7.

However cannons can not move, so if you need to protect your expansion, you need to build cannons farm there too. In the late-mid games or late game, when you have some money to spend, six cannons around a nexus are okay, but not in early game (unless you are going early expo). Dragoons and zealots can move, so you can protect any expansions with same groups of dragoons or zealots.

Therefore in limited money map, where you need to expand, a cannon farmer is a sitting duck. He or she is just waiting to be slaugthered. Hopefully more and more farmers read this article, so we would see less cannon farmers around. GG, GL, HF everyone.

SW)LittleAngel

Source protossnexus

So if they are inefficient why does everyone use them? Two important points are not considered in this very good analysis. Cannons provide early detection, that in itself is of value, it also provides detection with no gas cost and finally, unlike a goon, they do not require gas. All the way up to high skill level players, cannons will always have also a psychological impact-value on your opponent. Most people over value their defensive properties (good players don't), specially zerg players. There is a reason too for this based on unit AI micro issues when it comes to Zerg unit v cannon. Anyway only on the basis of early detection and no gas cost, cannons will always have a place in any protoss build & strategy.

Physician