This usually isn't the right forum for this topic, but here are the people who are interested in this idea. Would be cool if this thread became a sticky someday so that people in this forum can reference to it.
Everyone who has played in a team (or tried to join one in which he didn't know anyone), knows that there is the problem of skill. If you want to join a team, they want to know how good you are. If they need a player, they need to know how good they are. If you're searching for a clanwar opponent, you also search for a certain skilllevel.
There have been many tries to determinate the skill of a player, mostly used is the amount of Dota games played (like "you need to have played at least 500 matchmaking games!"), which isn't very accurate. A player who played 500 games a perma-attacking Sniper isn't comparable with someone who played 300 games with different heroes and tried to improve for serious, another guy just got his Dota 2 key, played 3000+ games in Dota 1 but has played only 50 Dota 2 games, and so on.
Most teams just write "midskilled", "highskilled", "mid+" or more creative things like "POWER RANGER NINJA SKILLED!".
I know that skill in Dota is a combination of many many facts. Experience, knowledge, situation estimation, decision making, lasthitting, spell using, and countless other things. But that's exactly the reason why I think the existing system ("low", "mid", "mid+", "high") is not satisfying.
I tried to come up with skilllevels and their description and I would be glad to hear your opinion about it. My "vision" is that someday you don't have to write "searching hs player!" or "cw 5on5 midskilled" but something more accurate like "cw 5on5 lvl5".
Maybe there will be a matchmaking for clanwars in the future, or Valve will give us visible rankings (since they have some kind of ranking system for their matchmaking anyway), but maybe that will never happen.
I also know that it's difficult to say "player x is skilllvl y", because he can be better in some aspects but worse in others. And some players don't play clanwars at all, but still are pretty skilled. But you have to start with something and improve it then
Level 0: Complete beginners, don't play very often, perma-attack, don't know much about heroes, spells and items. Usually you don't bother forming a team and playing clanwars at this level.
1: These players played over 100 games, know about half the spells of all heroes and what items to buy on their favourite heroes, a fair amount of them stopped perma-attacking and they rarely get killed by towers. Still not that interested in clanwars.
2: These players know about lasthitting and denying, they played most of the heroes themselves at least once, they understand about combining spells (like first stun followed by an aoe stun, or Enigma and some other aoe ultimate), try to use the fog of war. Some of them discover the might of wards and start using them. Usually at this skilllevel a player plays his first clanwar (and gets owned badly). Most of the public players stay at this level and improve only their skills in playing certain heroes.
3: They know all of the items and spells in the game by having played many games (500+), they start looking at some games of better players, played some clanwars, they start to understand the different roles in a game (supporter, (semi-)carry, initiator, pusher, hardlaner, ...), also placing wards more regularly and don't want to play a game without courir anymore. They understand the importance of the minimap, trying to get the runes, their mapawareness increases and some of them start counterpicking (like Sandking against Brood). This is the typical low-mid skilllevel in clanwars, which are getting more interesting than publics for some players.
4: Through their increased game experience they start using smokes more regularly, stacking and pulling creepcamps, carrying a teleport scroll with them and start helping their teammates all over the map. Counterwarding, organized pushes/ganks and over 100 creepkills after 30 mins is normal now, but their positioning in teamfights and skill/item choices tend to be bad.
5. These players know what items to build in which situation and against which hero, to change their skillbuild according to their lanemates and -opponents, their positioning in teamfights and on the lane becomes better, they understand the concepts and importance of map control, burst damage, focused fire, stun chaining / crowd control, animation cancelling, modelblocking, scouting (with spells/summons), they have a plan what to do in early/mid/late (like if they can win the lategame or not).
6: At this level the players usually played more than 200 clanwars, they attend at tournaments or leagues and play clanwars on a regular basis. They know most of what there is to know about the map, but they still lack coordination (who initiates on whom, when to teleport), make wrong decision (like when to defend or to push), their lanes may play too aggressive or too passive, there is still experience missing how to deal with certain situations or hero combinations (wisp-ganks, two lost teamfights, opponents doing roshan but two mates are dead). They're beating the teams on a lower skillevel without problems though, because they have more routine, more experience and more single/team skill than them.
7: These players play way more clanwars than publics, they start winning small tournaments and lose mostly against known teams. Their mistakes become smaller, their lasthits more (250+ after 30 mins), their hero/spell/item usage better. They try to optimize everything, illusions and summons scout, block, fool opponents or deny runes/towers, they drop hp increasing items before using salves, Syllas switch items with their bear during battles, ...
8: The pro teams which get seeded for The International and are famous. They can own a skilllevel 5 team with random heroes. There may be more different levels here, but who knows how you can distinguish them...