Strong Protoss Anti-Air?
Since the last question was more about Void Rays I concentrated on more diverse Protoss Anti-Air
Gateway
Since Protoss strategies usually revolve around heavy gateway units, Stalkers are more or less a must in anti air confrontations. The most important rule of Stalkers is: unless you are chasing, never blink into battle. This is key, because as a tool, blink is far more effective as running away or chasing than it is as an opener. Stalkers are a very fast unit, so the only time you should ever feel the need to blink into an enemy is when they're running away.
Blinking away has two important aspects to it:
- Mass Retreat
- Moving the Front line back
While retreating is often times a necessary thing, it's the latter, that makes blink such an effective tool. When you find yourself against engaged in a battle, you'll usually notice that your vanguard (front units) take the brunt of the damage. If you blink them away as they take damage, the damage will spread more evenly over your whole force and your Stalkers will continue to do damage from longer periods of time.
Protoss Air
If your build is designed around Air units there are two important things to remember:
- Phoenix can shoot while they move
- Void Rays can shoot while they move
Most people don't know the second one. The key to any Protoss air confrontation is to make it a mobile one. This is why the speed upgrade for Void Rays is so crucial. Now Phoenix and Void Ray have different use cases, Phoenix are effective against light, and Void Rays against armored. Based on what your opponent is going you have to adapt. If you're seeing Muta heavy, go Phoenix. If you're seeing Viking/Corruptor go VR. In a PvP its usually whoever has better macro or more upgrades who triumph... you know, unless you get High Templar
High Templar
Usually built out of an early 4 gate strategy, HT are one of the most powerful units in the game. Psionic Storm needs no introduction, but don't forget about Feedback. Feedback has the unit property of being amazing against unexpected units. Allow me to list a few:
- Ghosts (no surprise)
- Infestors (no surprise)
- Dropships (wait what? healing uses energy?)
- Phoenix (how do you think they lift)
- Ravens (as well as point defense drones)
- Battle Cruisers (Oh yeah!)
- Corruptors
- Even Mothership
I have definitely had games where I won with just HT/Zealot just because of how versatile this unit it. What's more they can easily be transformed into damage soaks (Archons) to break Siege Tank of Void Ray lines.
Having trouble against Mass Void Ray? Strangely enough Psionic Storm is surprisingly effective against Void Rays. Because of the charging nature of their attack, many players won't immediately move their Void Ray out of danger.
Conclusion
As always, the key to beating a PvP army often lies in doing something unexpected while your opponent is doing the expected. Use Observers to try and retain the advantage in the game of information warfare.
Your question has a lot of incorrect assertions. I have a feeling you are often sending small groups of phoenix against large groups of other units, which is not a fair comparison. The following tests, (which I encourage you to repeat as it is a great way to get a feel for how good units actually are) were done with no upgrades and no fancy micro - just a-moving both sets of units at each other.
"mutas slap around phoenixes." Not true. In my tests, 3 phoenix (which cost 450/300) handily beat 5 mutas (500/500) In this matchup, the phoenix has the advantage of bonus damage vs light. As a zerg I hate seeing phoenix on the board if I went muta.
"vikings slap around phoenixes." Not true. 5 phoenix just barely beat or lose to 5 vikings (750/500) vs (750/375) In this matchup, the vikings don't get any bonus dmgbecause phoenix are not armored.
"void rays slap around phoenixes." Not true 10 phoenix easily beat 6 void rays (4 or 5 left alive) costs are 1500/1000 vs 1500/900 Note that even if the void rays were charged, phoenix are not armored, so the VR's won't get a huge bonus against them.
"void rays get wrecked by vikings." Mostly true equal cost void rays will lose to vikings, unless they are pre charged, in which case the void rays can win.
Phoenix being weak is not the issue here. There is something else going on in your games that need to identify. When you watch the replays where you think your anti air is weak, try noting the relative amounts of each unit, and whether each side has upgrades, etc.