Power spikes

The moments you get stronger than your opponent.

From Silver

Professor Zéphyrinthe Academy's instructor

« Your champion grows in spurts, like a greenhouse plant: level 2, level 6, a finished item. That's when you fight, not when you're behind. »

The race to level 2
The first wave, then the first three melee minions of the second: that's level 2. You get there first.
One spell more: attack
Level 2 against level 1: two spells against one. You walk up and trade, and you win the trade.
Level 6 and a finished item
Your ultimate is up, theirs isn't, and you have an item more: a level ahead, the all-in is yours.
The classic mistake
You go all-in while a level behind: their ultimate is up, yours isn't. The fight is lost before it starts.

When to do it

Level 2 first: you have two spells, they have one. Walk up and trade.
Level 6 first: your ultimate is up, theirs isn't yet. It's the moment for an all-in.
Back from base with a finished item: you hit harder than a minute ago. Look for the fight.

Level 2 comes after the first wave and three minions of the second: the three melee ones. Count them, be ready to step up.
Watch their level, next to their health bar: one behind, you back off; one ahead, you press.
Count your gold before you back: finishing an item is a spike you can plan.

The classic mistakeGoing all-in while a level behind. Their extra spell or their ultimate decides the fight before yours is even up.

Good to knowA spike is a window: once they catch up in levels or items, it closes. Use it right away.

Iron to Silver

Before any fight, look at the levels: higher than them, you can go; lower, you back off.

Gold to Emerald

Race to level 2: stay in range of the second wave's dying minions, and trade the moment you get it.

Diamond and above

Know both champions' spikes: the level or the item where each one turns the matchup. Play safe before theirs, all-in on yours.