The main debate is over how to boost Shaco's attack speed: with runes or items. Shaco players generally always choose runes, specifically Alacriti, but when you need other runes, for example, when the meta has changed, you have to give up Alacriti. The only adequate replacement for this rune is Static Shiv, given the high cost of Berserkers. Cashback works well with Treasure Hunter, but are we ready to give up Relentless Hunter? Shaco's entire build revolves around this. Since Assassins now have many useful, very powerful, cheap items, it's impossible to give up Umbral Glaive and Opportunity, so there are very strong alternatives to Static Shiv. Depending on your own feelings, whether Shaco needs more run speed and attack speed from Static Shiv, or to focus on the usefulness of the Cut Down rune + Alacrity and Relentless Hater, ignoring Cashback + Treasure Hunter and Aproach Velocity. However, one thing is clear: it is impossible to buy Berserkers due to their excessive demands.

Statik build:
Pros
- Attack speed
- In fight movement
- Scales good. Cashback + Treasure Hunter = additional ~1k gold
- Aproach velocity move speed and the in-game opportunities it gives us
- Faster farm, faster objectives (dps)
Cons
- Losing assasin potential
- Losing useful alternatives from lethality items

No Statik build:
Pros
- Out of combat move speed (Relentless Hunter), Shaco very need it to assasinate enemies and gank everything non stop. The lack of movement speed is especially noticeable in the mid and late game when you need to kill backline carrys.
- More dmg since 2nd item and gap getting bigger with every lvl and item, scales assasin potential better.
- Stronger first lvls
Cons
- Lack of in-fight move speed
- Lack of attack speed sometimes
- Scales slower
- 100% need backstab Q, if u miss u lose tons of dmg

I pick relentless hunter + cashback + statik. Relentless hunter value too big and it works all game long, just like Cashback, but not Treasure hunter, usually u cant proc treasure hunter 5 times, its always like 2-4 bcs of some guys playing unkillable tanks, so its overrated.

This is basically my draft, and I'm constantly updating it, so don't be surprised if you come in and everything has changed.

My build vs Any other random "pro" Shaco is literally:
Swole Doge vs. Cheems. Gigachad vs Chudjak
And the last hope of humanity

Im not teaching you to play, its not a gameplay guide, but the most efficient and detailed build ever existed in humanity.