It's kinda sad that you can judge if a game is won or lost before its even begun
With op.gg, you can almost say with a pretty high degree of certainty which game is gonna be won or lost.
This is what you should look for (in order)
- Smurfs or boosters If a booster is tryharding, most of them will easily get 90%+ w/rs up to Diamond. Your game is most likely over. Rip in peace in rip.
You have a booster/hard smurf? Free LP
- Autofills/1 tricks (not on their OTPs)
And this depends on the "degree" of autofill.
Low degree autofill (you can get away with it): someone who isn't super foreign to the role gets autofilled in a passive matchup (i.e. mid player getting autofilled top in a Cho vs Mao matchup).
High degree autofill (unlucky): someone who is completely foreign to the role decides to lock in a high skill champ in a skill matchup (i.e. instalock Nidalee first time btw against Graves jg main).
Ever see someone with a 78% win rate on something like Irelia, only to instalock Riven with 33% w/r? Yup. I can't possibly expect Riot to predict this - but it feels awful.
- Team comp
At least w/my experience in my elo, you can get away with shit team comps with enough snowball. If the previous two are in your favor, you're in the clear most likely. However this makes it hard to judge.
Yes, these even out over time, but it fuckin sucks to get into promos and realize the game is already lost...
Now sometimes, you can overcome these with your own play - but unless you're hard smurfing its really difficult.
Edit: Last game in promos, predict I lose b/c autofilled jg picks Lee Sin first time, mid firsttime LB (and autofilled)
While enemy team has a LCS composition, but lets see (their pyke has a 28% w/r maybe in our favour - but idk if its enough)
Edit: SUPRISE, we lost. Lee sin obviously had no idea what he was doing and couldn't insec at all. No suprise.