did RNG really decide who went on to the knockout stage?

The reason that Royal advanced was because they beat TSM head to head two times, so they hold the tiebreaker. If they had gone 1-1 they'd have had to play a tiebreaker and if TSM had won both games they would have gone through without a tiebreaker over RNG.

2 head to head games are played between teams. If each team wins 1 head to head game, - tie breaker will occur if their scores are the same

TSM had the same score as RNG but their head to head record was 2 losses. This means, even if they had a third game, they would have only won 1/3

With that said, TSM lost. 66% of their win was against the weakest team in groups

cause they stood 2-0 head to head vs TSM

I had the same question when the casters announced that RNG were going to quarterfinals, but this has been explained numerous times since then on these boards.

TSM could have had a chance to face RNG in a tie-breaker if they could have beaten Royal at least once but instead Royal took TSM over their knee and gave them the D Twice no need for a 3rd time is there?