/u/yuanek1 explains in detail how he went to Challenger playing only 2 or 3 times a day. 

Hi there! I'm CrazyYuan, a fresh challenger player from EUNE. It took me exactly 101 games to reach Challenger, playing 2-3 games a day since the ranked went live. I just wanted to show that you don't need to grind a lot to get better and share some tips which helped me made my final push from D3 to Challenger along with a detailed explanation of the build I forced.

You can read /u/yuanek1's entire Casual Player to Challenger guide here.     We highly recommend it. 

Key Points

• He forced a Brawler / Assassins build.
• Core Pieces - Rengar, Pyke, Kha'zix, Rek'sai, Cho'gath, Vi, Warwick

• Core Items: 
  • GA - Rengar
  • BT - Rengar
  • Morello - Pyke or Cho
  • Tear - Pyke
  • RFC - Rengar

A weak early game is to be expected as you are going to eco hard.   He explains what to build out in respect to weapons, what pieces ot save, etc. 

Once you hit the midgame you should be at your strongest and this is where you need to make gains.    Lategame you lose power, but top 4 finishes should be the norm. 

Will you try it?  Thoughts?