I tried, I learnt, I got 1k1 MMR

Hey Xyros those spells that you just linked about ravage and black hole etc, it is excellent to win games with! you can have so amazingly positive impact on a game if you just play it right, like getting 5man holes with enigma etc, its game breaking heroes.

Using global silence when the enemy initiate allowing your team to counter initiate and **** them up, etc

and you need to balance the teams lineup, as in hardcarry/support/Mid/semi-support/semi-carry or something similar, so if there is no big initiator hero in ur team, you should consider picking it, if there is no carry (fat chance all noobs go carry...) you go carry, pick whatever the team needs most, even a support can have an insane amount of game impact, a guy i know went 60 wins 3 losses solo queue as support, he carried laning phase, ganking mid, counter ganking early with scrolls etc, always warding and dewarding = win games

Most of all it doesn't really matter what hero and role you play, as long as you play your hero better then they play their's :)

I think the positions that will have the most impact are the supports. Warding and controling the flow of a battle, setting up ganks, saving the cores, lane control etc etc all those things are something the cores will expect of you. If you even do a mediocre job on all of them your team will most likely win. If you do a very good job on all of them you're fy or Fenrir or Zai. Being good in all those things is very very hard and requires a lot of experience and knowledge.

One hero I like in particular is Earthshaker his skills can have so much impact in fights and ganks. Since Fissure does not only stun, but also create a physical barrier for some time it's a skill that is so useful in fights even lategame. And Echo Slam just tears through a 5 man push like it's tofu.
Sand King is also really great, but can fall off lategame since you won't have anything that goes through magic immunity (unless you go Skull Basher/ Abyssal Blade).
Witch Doctor is very strong with the physical ult, especially with Aghs and the heal is just so op.

So overall I recommend playing high impact supports or you need to be so good on cores that you can crush through everything.

So for a little update on the OP.

Loaded my 2nd smurf, now 60 games and 62%wr overall. Started to concentrate on these 5 heroes, picked purely because they're my highest KDA.

WD - 66%wr, 3.1kda
Razor - 88%, 4.9kda
CK - 80%, 3kda
SB - 66%, 3.11kda
Lina - 60%, 3.4kda

As many of you mentioned above, I've been working on my decision making by watching replays. OMFG it does lead to some hilarious moments of wonder at my stupidity :) Productive though.

Also paying more attention to the enemy has reaped its rewards. Most importantly, baiting out and counting the stuns as they come out in a team fight.

dude.you are only 200 games in on your MAIN. people playing in 5K-6K have dedicated YEARS to dota, not months. It takes time. It will come. Grind hard. PIck TB.Win games.

5-man Black Holes are few and far between once people start learning that clumping up together in a bolus is a dumb idea.

As discussed in the Tide vs Enimga thread There's only so much Enigma can do in Teamfights without Black Hole. Teams may be happy to wait 3 minutes for the next fight to happen in Low Skill games, but as you go up, Teams will realise it's safer to fight while Black Hole is on Cooldown and will do everything they can to make Enigma waste that Ult.

Again, Silencer is basically a walking 2-minute Ult, yes he has a nice Right-Click and a couple of situationally useful Nukes...but that's it, and even with Agh-Refresher, there are a lot of Heroes who can jump in, pop a Spell and then fight with nothing more than Right-Clicks and Items, e.g. Slardar, Lycanthrope, Nature's Prophet, Terrorblade, Phantom Assassin, etc. etc.

Even if they need time and positioning to use their Spells, there are plenty of Cores that can happily buy Manta Style/ Eul's Scepter of Divinity/ Diffusal Blade/ Black King Bar and remove the Silence.

heheheh I realise that.

I'm not looking for 5k+ MMR. The reason I'm on my 2nd smurf is that I find it a little ridiculous that my 1st calibration was 1k9 the 2nd was 1k1.

AFTER learning a hell of a lot more about the game, playing with the appropriate attitude (ie non-yolo) and actually caring about a result I dropped from 1k9 to 1k1.

Seeing as I'm playing the same game, repeating calibration doesn't make that much of a difference to me.

In one game i got a 5 man (Thanks to an Earthshaker walking into it...) followed by a 4 man and another 5 man (with a couple of 2/3 man's thrown in).

It was my best game. My friend even did a Merlini-esque "BLACK HOOOOOLLLLLLEEEEEE!!!!!!" on the first one. Nothing feels quite like landing a great 5 man Hole (fnar fnar), especially is it leads to a wipe.

Unfortunately most games people do split a bit more, but i have started to pick him more situationally (thanks in a large part to advice in the other thread).

I haven't even done my calibration yet. Played 250ish games, 55%ish winrate (http://www.dotabuff.com/players/54450733). I still don't think i can consistently perform so that calibration will be fair. I dont find that a problem though, i'll keep playing pubs, learning, and i'll do the odd Raked every now and again. If i calibrate and it's just awful, and i am far off my friends, maybe i'll smurf. But until then i'm not going to sweat it. I don't want to be in a semi-/pro team or anything.
Most of the enjoyment i get is from playing with 3 or 4 friends anyway, then your calibration doesn't matter so much as you know what your getting.

Romark

You guys really shouldn't focus on winrate especially if the quality of the games are low level. If you're getting 55%+ but you're below 3k level then it's really not much else to say but that you're playing against nubs or inexperienced players.

Players really should not focus on their mmr and should focus on improving their play, the MMR numbers are just an estimate of your skill-level for a period of time. If after 1000 ranked games and you're at 3k, then you're a 3k mmr level player but if you only have 50-200 games of ranked then there's more room for estimation and "calibration", it won't be as accurate as someone who has played much more.

Point is, focus on improving. The higher level the games the more fun you get out of dota, IMO.

edit:

If you look at reports of players that bought 4k or 5k level accounts because they think they are, their mmr dropped dramatically. Even if at one point you have a high mmr level it won't matter if you're unable to pass it after a certain period of time with a certain amount of games. It should be more apparent if you lose a lot of games in that mmr level too.

Valve keeps good players MMR's low intentionally otherwise they could be potentially picked up by pro teams which could destabilize the established "stars" of Dota 2 competitive scene like Arteezy, NeVo.Dondex etc which makes the game less profitable in the long run.

This makes perfect sense!!