From The Trenches: The Best Pub Items
As a disclaimer, my MMR wavers between 3.5K and 3.7K, perhaps a little above ELO or MMR hell (even partying with friends ~3K), but it is well within a meta that is dominated by Snipers, last picked Pudges, Rikis, and cliff juggling Nature's Prophets. And they're all on my team. In the course of my games I've found that there are some items that are underrated, deceptively powerful, and even straight overpowered. Let's start with the most obvious one.
Shadowblade
Shadow Blade is a nightmare to play against in a meta that says detection is for tryhards. After all, who buys Dust and Sentry when you have five cores? It's an item often used for initiation in competitive play, but in trench play, this item saves the lives of the most annoying heroes.
Sniper, Drow, and Nature's Prophet are the top three heroes that use this item. Here's a familiar scene: Drow is pushing the lane past the river, 2-3 heroes TP to defend the tower, someone runs around to gank, and she casually activates Shadow Blade and walks away. Then everyone quietly fights to last hit the remaining creep wave, humming along before they repeat this cycle again. Can someone please buy dust? Anyone? Ok, I've bought it. It's on the courier. Take it.
Sentry Ward and Dust of Appearance
Sentry Ward and 
Dust of Appearance are mythical items. They don't exist, but we believe that they once wielded the power to reveal an invisible Shadowfiend who walks into the middle of our group and teamwipes us with his ultimate.
In pubs, Sentry is often used to de-ward, but it's rarely used when defending or when pushing. I actually don't care about de-warding. Who uses wards? Even then, the game ends up with two opposing supports in a mini game of warding and de-warding the same river rune. However, I have seen too many team fights lost due to an invisible initiation by Shadowfiend or Nyx. Much like how your team will keep making the same mistakes and dying to these heroes, you can guarantee that they will continue to feed over and over by running into your well placed Sentry. However, sometimes it doesn't even matter if you can see the initiating hero or not:
Magic Stick
You can buy 
Magic Stick from the side shop, and it's such an efficient item that you don't need to upgrade it to 
Magic Wand. For 200 gold, it will help you sustain in a lane where players will most likely spam their spells without knowing you have a wand. More importantly, it seduces players into making the wrong choices. Who really checks if you have 10 charges on your wand when diving? They don't even know you have items. Just don't forget to activate it when you want to turn the fight.
TP Scroll
135 gold to purchase one of the best items in the game. 135 gold can save your life against pubstompers like 
Slark, 
Bloodseeker, and even 
Bounty Hunter. I would gamble that he isn't saving that Shuriken Toss for a timely interruption.
"Always carry a TP scroll" is one of the mantras of Dota. Actually, carry two TPs, just in case. It should also be one of the first purchases for a support player (these players do exist from time to time). In my games, the only time I see multiple TPs to one tower is to compete for farm in an empty lane. Five TPs, one creep wave.
TP support is crucial to defending towers and dives from the enemy team. I see this understanding appear in late game situations, but rarely does it happen early-mid game at the T1 towers. I can assure you that their team is not calculating whether they can push or dive successfully if your support came in. They just do it, and you have the power to punish it. Buy TPs.
What really matters
The best items in pubs are items that are inherently good, but some are even better because of the lack of the average player's map awareness, game sense, and understanding of hero mechanics. Also, we have a reluctance to buy items that don't give some immediate sense of reward. We buy items like 
Power Treads, 
Drum of Endurance, and 
Blink Dagger because they give us an advantage the moment we have them. We do more damage, we have more HP/mana, and we can blink.
However, items like TP scroll, sentries, and magic wand are for the future. We buy them to prepare for future engagements. This sort of planning isn't fully formed yet in pubs. There's a Riki and Nyx in the game. Do you buy sentry when they're approaching lvl 6, or do you buy them after they've gone on their killing sprees ? Part of improving in MMR is in mechanical skill: last hits, skill and item use. But a big part of the game is psychological. Reduce the errors playing against invisible heroes. Trick enemies to initiating, and get your teammates to TP in to support. Buy some detection. A little can go a long way.
in my opinion most cost efficient items are drums,aquila and stick. I dont usually get aquila and drums together because two cheap items fill your inventory and you cant buy dust or sentry if you need. For detectionwise only slark with sb scares me, the others (drow,prophet,sniper etc.) are easy to kill when you have dust. Slark is just nightmare. İf you use dust against him he will use dark pact, if you use sentry he will pounce away. Only way to win against him is purchasing gem or having bloodseeker in your team. Btw ty for your detailed post.
I have 3650 mmr and haven't seen drow or sniper for a long time, i think your description fitting more for ~2500 or even 2000.
Also, Calmy, Slark's ult can't be revealed at all.
^ voids ult reveals it.
Also, I haven't seen this shit in a long time.
Then again I'm usually between 4000-4100 rating.
Gaben, Calmy means to say getting a gem for a Slark that is going for/has Shadow Blade. And yes, I agree that the description is more fitting for way lower MMR games. I get horrible players in almost every single match but I have never seen the "5 TPs, 1 creep wave" strat before.
The last player teleporting must be someone with lots of patience.
@Gaben I'm most likely the one playing Drow or Sniper. :)
No drums, tranquils, midas? I'm dissapointed :(
Dr. Nele Karajlic I remember when I first started playing... midas and tarrasque on every single hero. My first matches here in dota buff always make me laugh.
I'm ~3500. Plenty of Snipers, NPs and Pudges. Not many Shadow Blades but even if they do, we always have dust.
@Dr. Nele Karajlic That'll be for a post another day. These items are just in recent memory.
3443 and EXACTLY where I belong. huehuehuehue
100% win Rate against riki confirmed. 4,3k.
im confident there must be some regional variations then. i'm ~3.5k and I see drow once every 100 games at most.
You can say whatever you want, I play at 3,6-3,9 and the quality of games have improved drastically over the few months
It doesn't really matter what MMR you get. What matter and always it will is keep calm and carry TP :)
So basically, anything below 4k is major trench right?
This is all about invis and counter-invis item (not counting TP and stick). You said pudge earlier, do pudge buy shadowblade then?
anything below 4.5k is the trench
There is a big difference between AP 3500-4000 and CD/CM 3500-4000 as well. In my experience, most matches in CD/CM are at least players trying to play the right way. There are, of course, exceptions.
From the comments I can see that people just love bragging about how "good" they are by being 4k+ (typical humans). Believe it or not, the trench starts below 2.5k. I know the scale pretty well by now since I've met so many people scaling from 1.8k to 4.9k and even tried to help a few get out of the trench, but its a long long process.
People will say "oh God i'm in the 3.8k Bracket trench tier omfg", I just treat them like Facebook pictures captioned "I'm so Ugly".
Its a way of them getting noticed for what is actuallly an OK Ranking.
But there's dunces everywhere from what ive seen. People just get carried through TBD Ranks alot and end up in 3-4, or even 4-5k Games and ruin Rankings for others. Tis the way.
anything below 6.5k is the trench
As people saying, it would make sense to put region in the article since US and EU MMR ranges and playstyles are differenet.
This article isn't about MMR or which heroes you see more often, it's about spending a tiny bit of gold on support items (especially teams with 5 carries) because dust/TPs/wards are never not useful.
I completely agree with this article and it's one of my favorites on the site. However, what I don't understand is why wards, dust, and TPs have such low winrates (I'll post links at the bottom). I understand that winrate for these items is calculated at the END of the match, so it's likely they'll have been used up by then, but it just seems like a good player who carries these items ought to have higher than a 30-35% winrate. What am I missing?
Observer (36%): http://www.dotabuff.com/items/observer-ward
Sentry (31%): http://www.dotabuff.com/items/sentry-ward
Dust (35%): http://www.dotabuff.com/items/dust-of-appearance
TP (46%): http://www.dotabuff.com/items/town-portal-scroll
Shadow blade, for comparison (56%): http://www.dotabuff.com/items/shadow-blade