What you should focus on is your `Tempo`.

Imagine `Tempo` as having the need to generate as much impact as possible throughout the entire time.

League is not only about making right decisions, but also about making them as fast as you can.

Especially applicable is `Tempo` when playing early-lategame champs such as Shaco and most other assassins. As your strength decreases, you goal is to close the game ASAP, meaning that you want to execute:

- gain advantage
- use advantage to gain even more advantage
- use advantage to get closer to enemy nexus
- destroy enemy nexus

as fast as possible.

Most lower tier players for example usually don't increase the pace, once they got an advantage. Quite the opposite, they usually relax down, thinking they already got the lead they need to win the game later anyway, which is why most assassins have such terrible winrates on lower tiers.

A master tier player will throughout every second of the game try to play it as fast as possible (taking the camps as fast as you can, optimizing the routes to not waste any time, make fast decisions for the sake of speed, just to not lose `Tempo`, e.g. backing off of a gank as soon as an advantage is unprobable, just to not waste time, where you could instead take scuttler etc. )

When practising `Tempo`, a good start is to keep track of your gold. Always try to beat your @5 @10 and @20 minute marks, you will figure out where you can optimize your gameplay, if you just follow this tracking technique. Later on, you will have to integrate map control through objectives aswell, but that will be much more easy, since you understand the concept of tempo and how to estimate value each different decision has.

IMO `Tempo` is one, if not THE biggest, determinatior of gamecarrypower and raw skill in general. It has a montrous learning cap and a lot of impact, so it is definitely worth investing dedicated tine into it, when trying to climb/getting better.