choosing a champ that you can play effectively that works with your team comp ....
example: i main support and i can play over 10 of them effectively and i pick my support based around what my team comp is and what they need to do to win. and i try to pick my support to help that... like a game last night my team had an ekko top, yi jungle, kat mid and ashe adc, i picked braum...
i have cc, shield , can peel, knock up with ult etc making it hard to get to yi and kat and i can keep ashe safe in lane... and i set up and allowed them kat/yi to carry game going 10-4-9 and 17-10-6 while i went 2-2-20
and when i play top i usually will pick the tank/cc champ regardless of my match up cuz jungle went damage no cc, mid is damage no cc and we have a utility squishy support
one game i picked maokai into kayle knowing i should lose lane and lose hard... but knowing that i can be useful from behind based on my kit and what i provide to the team fight situation.... i did ok in lane being passive and farming... come mid/late game i was the team fight monster tank we needed.
so its not what counters your lane, it what ties your team comp together making their strengths stronger and hiding their weakness on a champ that you can play effectively
but to pick a champ cuz they counter another champ and you dont play that champ is hurting your team... you be better off playing your main and just alter your play style of your main
