>>1465317Irresponsible Captain Tylor (skill disguised as dumb luck)
Kaiji
Talentless Nana
Battle in 5 Seconds is a shitty battle game anime but MC has an ability where it's whatever the opponent thinks it is meaning he has to outsmart them to win
One Outs
Akagi (not necessarily a weakling, but uses skill to overcome enemies)
Legendary Gambler Tetsuya (same as above)
Trigun to an extent since he doesn't want to kill people
Certain Magical Index is about a dude who is pretty much always outmatched
Kyou Kara Ore Wa is about two guys pretending to be delinquents and usually using underhanded ways of winning the few fights they have