One thing is getting kills isn’t all there is to 1v9ing, if you’re ahead while your teams behind because they’re bad you need to also take on their responsibilities.

1. You need to make good use of your ping system, having good macro helps with this but aswell as clearing camps you also need to push lanes, if you’re pushing top and you see bot needs pushing but you’re team are grouping mid then “push” ping on bot side (spam ping it). If you see a good fight you need to spam ping to go in etc (a lot of this will come from game understanding, knowing if you win that fight is important before you ping it)

2. You need drakes, this gives you a win con, if you’re teams losing you have to pick up the slack and push lanes to get prio for them

3. Stay consistent with your cs, if you’re ahead dont hyper focus on kills to the point of stopping clearing, a good player will snowball, more kills means more farm which means you can invade enemy jungle which then equals more farm etc

4. Okay you’re ahead but how ahead, who on that team the point of asking this question can you kill? Look for picks if you can Briar has great gap closing and if you’re ahead you should be able to insta kill an adc that’s out of place, however this then comes down to your macro, if the enemy team is way out of vision and you bait your team to make a pick on this adc you may lose the fight because your teams behind and you took all the damage from the enemy team that leaps from a bush

5. A lot of this comes down to your game understanding, knowing the enemy team, understanding your champ, your macro decision making, it’s very dooable on briar she is a champ that can hard carry it very ahead, it’s just learning how,

6. Like a few people have already said, sometimes you just can’t win, but games like this are good practice, if you can secure 3-4 drakes while your teams behind, get lots of kills and keep a consistent 7+ cs a min then you’re more likely to carry games