hey I am looking to find out what the best champions for 3v3 ranked are, and how they fit in, in terms of team compositions and possible combinations. I want to improve my team composition for this, and getting some tips would be of great help
Bruisers, CC, more bruisers.
Mundo and Rumble are gods. Other than that, Riven is pretty nice, gangplank, diana, maybe teemo. Really almost any bruiser.
Fighter/Tanks tend to be pretty solid in that map.
Generally speaking mages/assassins/marksman get their defense for free in range and/or mobility and need to build damage to kill things, where fighter/tanks get damage for free and need to build their own defense.
Against only 3 opponents in a map pushing a lot of early-game pressure: counter-building your opponents can be really imposing.
I'd just say the key here is rushing defense: the difference between a tanky/fighter rushing Omen vs. Kingblade is night and day. When they're actually tanky they're a nightmare, when a tanky DPS decides to not be tanky they're generally a joke.
Mages are also really solid in Treelines. Riot kind of over-compensated mages being weak in Treelines by giving them exceptional itemization in that map.
The best champions there are mostly in the fighter/mage or tank/mage by combining those strengths together.
are all pretty WTF.
Especially because you can get tanky and DPS at once, in higher-than-Rift qualities with stuff like 
and 
You could also check the win-rates in LoLKing They track win rates for ranked and normals for Treelines.
I'd recommend looking at the monthly searches, as in my experience daily and weekly searches fluctuate to much between check-ups to really offer any definitive leads. Also larger sample size = better.
