Just thought I'd repost this informative post by Fenix which I just read on the SC2 forums. Fenix's profile - http://us.battle.net/sc2/en/profile/384884/1/Fenix/
For the sake of seeing if it was really difficult. I demoted myself to bronze league, just to get back up into diamond. I wanted to see if it was really as difficult as everyone in the lower leagues says it is to get promoted.
To start, i'll tell you a little about myself and playing style.
-I am not an excellent player. People like Horst and Funkmunk make me look like a casual.
-I consider myself to be a high Platinum/low Diamond (more on that later)
-I started in gold and eventually worked my way to diamond. (That was when i first got to Diamond a month ago)
-I excusively play Protoss and nothing else (deal with it).
My playing style:
-My biggest macro problem is knowing when to expand
-My biggest micro problem is using my control groups effectively (keeping Zealots at front ect ect)
-My apm is 55-70 on average and about 120-150 during fights.
-I prefer getting Dark Templar rather than robo tech.
Now that thats out of the way, i'll take you on the brief trip on what my experience getting through all the promotions back to diamond was like. I will also explain how i felt each league was like and their overall playing abilities. It took about 55 loses and then one win to get to bronze. NOTE: don't bother telling me you do something people generally do on a different league. No one cares.
-Time to get out of Bronze was 2-3 hours
There was alot of "all ins" in this league. Many people also liked to call me retarded or a noob. 3/3 cannon rushes worked in this league. Only time i lost was to get promoted. Void rays, MM, and 6 pool was most popular. No one scouted.
-Time to get out of Silver was 1 day
This is where i personally feel the game is really starting to be played although i did fend off a worker rush soon as i was there. Many people managed to catch me off guard and i had to switch to actaul strategies instead of just making 10 units and killing their base. 3/3 cannon rushes worked in this league. Lost about 4-5 times i think? Builds became more diverse. A couple of people scouted.
-Time to get out of Gold was 1 day
Scouting finally has become a norm, even if it is to find where the enemy is located. Rushes become more clever and people start hiding their tech. Started to put effort to get out of this place. Cannon rush worked 3/3 times (although i had to start making them outside the base first). Lost about 8-12 times. Some people upgraded in this league.
-Time to get out of Platinum was 9 days.
This is probably the most underrated league in Sc2. Many people don't give Plats the credit they deserve. Had to put all my skill when in this league. Cannon rush worked once. Speedy 4gate and Zerg fast expand become super popular. Scouting becomes annoying since people patrol their workers around. People upgraded in longer games. Roaches also very popular.
Loses is about same as wins.
Some Diamond players are just awful, whilst others blow my mind with their skill.
People begin to micro their workers to deny your making buildings. Sentries are hugely popular and counter-attacking becomes a main style. Many people take map control before killing you for a sure win. Cannon rushing never worked. All sorts of different strats have been thrown at me which keeps me on my toes throughout the whole game. I don't mean to glorify the Diamond league, but many of them are incredibly good.
In the end, If you have been stuck in the same league for a super long time and can't seem to get promoted, chances are you probably belong there. It doesn't matter what "you consider your skill as". You are where you are. It's taken me 11 days to get 4 promotions
Even if you sit on the top of your division, it's not some glitch thats holding you back, it's just you.
TL;DR-Getting promoted is easy.