Dustbowl 2-2 A Case Study
(I will be quoting my own material for easier reading purposes)
The cons of a sentry nest: Ex. Dustbowl 2-2
We all know this spot, its next to the CP, right on the sign with the small health and metal pack, and its a straight shot right out from Red spawn.
It seems balanced enough doesn't it? It can't shoot past the rocks and BLU will have a height advantage against it. So this works out? Wrong.
The first thing we need to establish is the basic mentality surrounding a sentry nest. A sentry nest provides health and ammo, and with the level 3 dispenser it is very effective at doing that. This health and ammo will keep people around the nest, causing it to have a very high population density
A high population density effectively negates the spy and his sapper, which rules out one of the major counter to the sentry. Another problem is that all these people will absorb and counter attacks meant for the sentry.
A soldi behind the rocks on Dust 2-2 should be able to kill the sentry because he is out of its range, right? But due to the ammo that the dispensers provides, the other team can just spam the rock and pyro's can airblast shots away, completely negating this counter.
The sentry gun is on a health pack and metal pack.
This allows the engineer to build his stuff up without too much hassle, which is fine. But once you have a lvl3 dispenser up, there is too much health, and too much ammo, and a gun humping engie can survive a standoff against a heavy with all this supplies.
The sentry nest is also extremely close to spawn.
This lets the engi build very rapidly, and is too much when you add on the preexisting metal and health. The engineer has too much supplies next to him and can turtle extremely well.
This also allows team mates to escape ubers, while the uber is busy with the sentry
BLU has a height advantage, which should allow them an easy time with the sentry.
The height advantage is actually one of the biggest problems with it. The height causes most ubers to run off the ledge, but if you fall off, the sentry will hit you in mid-air and send you flying away, nullifying the uber. The height advantage is terrible.
You have the wall blocking the sentry from you.
The problem with the wall is, is that projectiles (stickies and rockets, which are the most effective tool against sentries) shoot from your right hand, and the wall is on your right. So you can't effectively "edge" against the sentry, instead you have to pop the full way in and out, leaving you more exposed to sentry fire, and extremely exposed against spam from the defense.
There is the fence blocking it from hitting you on the CP.
The fence only saves a bit of the CP, and a good sentry nest should never be that close to a CP. A good nest blocks a route to the CP, but doesn't cover it, meaning that defenders must stay back to protect the CP from scout and spy ninja caps.
To counter act most of these problems, a good sentry nest should be good becuase of their location, not the metal. The metal should be further away forcing engis away from their nests, leaving them vulnerable, and to prevent them from turtling. If they build their sentry right next to the metal, that spot should be a very bad spot. The wall blocking the player from the nest should be on the attackers left hand side. And the nest should not be directly covering the CP.
But the most fundamental problem with the nest that you cannot counter with just the map is the fact that people huddle around these nest to grab the health and ammo, and that this health, ammo, and large group of people keep attackers at bay, and spies (the hard counter) away.