Typically, after each major update, the community takes some time to adjust to the new meta. Therefore, if you take advantage of this period by using the strongest compositions in the meta to climb ranks, then “top 1 is easy.”
Here are the compositions with the highest top 1 rates in patch 10.12:
4 Marksman Composition – 27.5% top 1 and 77.3% top 4

It may be hard to believe, but the numbers don’t lie; this composition has a 77.3% chance of reaching top 4 and a 27.5% chance of hitting top 1 – clearly showcasing its dominance in patch 10.12 these days.
Regarding the strength of the composition, the frontline trio of Gnar, Nautilus, and Wukong will serve as tanks and provide strong crowd control. In the backline, the 4 marksmen will be the main source of damage. Among them, the two key carries with the highest damage are Jhin and Teemo. Before reaching level 9, you can choose to use Karma or Lulu depending on whether you want to get the Shadow or Cosmic buff.
Mystery Protector Composition – 19.1% top 1 and 51.8% top 4

Essentially, this is an upgraded version of the previous 4 Protector and 4 Mystery composition with a slight enhancement from Urgot and Cassiopeia. The frontline still consists of the familiar 4 Protectors, with Rakan and Xin Zhao needing to reach 3 stars with appropriate items. In the middle lane, Cassiopeia will provide sustained damage with her ability to continuously spam skills using Blue Buff. If she also has a Guardian’s Armor for a shield, it becomes very challenging to take her down.
In the backline, Urgot may feel a bit “underwhelming” as he doesn’t have items and isn’t a carry in this composition, but if he has enough energy, he can still eliminate an enemy quite effectively. The Mystery champions in the back will also serve as a shield for the Assassins and support the frontline.
Cybernetic Trickster Composition – 18.6% top 1 and 59.6% top 4

With the introduction of Vayne, this composition can activate 6 Cybernetic champions very early without needing Ekko. In this setup, the main carry is still Irelia with 3 items: Guardian Angel, Infinity Edge, and Giant Slayer. The roles of tanking and dealing damage will be evenly distributed among the Cybernetic champions. After activating the Cybernetic trait, you can choose to funnel more items into Ekko or Riven as a carry.
Zed Blade Master Composition – 16.3% top 1 and 48.9% top 4

This composition requires a bit of “luck” as you need to have Zed, Yasuo, and Shen all at 3 stars. Notably, Zed needs the Blade of the Ruined King to activate the Blade Master trait. When this happens, a single activation of the Blade Master trait will allow Zed to trigger his ability, dealing both healing and significant damage.
The tanks and time-buying champions will include Shen, Riven, Irelia, and Fizz. Additionally, there is a secondary carry in Master Yi, whose true damage combined with 6 Blade Masters can still provide Zed with some assistance.
Bruiser Gunner Composition – 16.1% top 1 and 61.7% top 4

In this composition, the main damage dealer is solely Jinx. The 4 Bruisers will serve as the frontline to buy time for Jinx to unleash damage, especially as having 3 champions with strong crowd control can hold the enemies back for a long duration. In the backline, Janna will help Jinx maximize her damage output thanks to her tribe buff and her skill.
In the late game, when you reach level 9, you can adjust your champions depending on what buffs the opponent’s composition has (Frontline or Mystery). Then decide whether to keep or swap out Janna for a pair of Mystery champions like Lulu + Karma or Soraka.