My summoner name is Matrealt and currently I don't have much standing in the ranked ladder because of how much time I spend going to college nowadays.

I've been playing Master Yi since I started league at the end of Season 2. He was my first champion ever and even without knowing how to do much of anything he won me games in 3v3s.

3.5 years later he is my Jungle main for Ranked 5v5 Solo Queue and my win rate is roughly 66% with him at all times.

Playing him effectively depends on how the Meta is shifting.
As of writing this it was the Tank meta (5.18) shifting into preseason changes of early game bursting (5.24).
As such I had to change up my itemization and the masteries to fit all Riot's changes.

Attack speed will keep you going for the entire game and proc your Q, E, Cleaver, Devourer damage, devourer extra hit, and Blade of the Ruined King passive.

The 10% CDR at lvl 18 is because no build with Yi in this guide should get past 30% CDR with items, which is where the extra 10% comes in at the end.

Everything else is to survive the jungle and ganking.

Subject to much change over the preseason.

Right now Thunderlord's Decree is OP as skittles so I changed the keystone to that from Fervor of Battle.

More changes are afoot so I will be on my toes.

Always max in order:
Q - Main skill
E - Extra scaling AD damage on hit and true damage when you need burst
W - Your defensive stance when you need to not die/wait for your team to help

R is just everything you need and should be getting it every time it's available

ALWAYS START BOT LANE!
DO NOT ATTACK MINI-MOBS!

Get your ADC and Support to help you ward the 2 areas of entry into your jungle along the river which are usually the small river bush below mid lane and the area just about in front of the dragon pit.

Get the Krugs/Gromp and try to get support to tank some damage if you can. Then go to your main buff and draw it into the bush right next to it just enough so you can see your enemy jungler coming if need be. Do not smite your main buff, just focus it down.

Go across the jungle to the scuttle crab on the other side which should spawn 1-5 seconds before you get there and don't use any abilities on it unless you're at full mana.
This is your HP recharge time for going to your next few camps.

You can pick what you'd like to go to next, but...
If your blue buff is still up, go straight to there and take it. Smite if you need mana to use your Q or W to finish and heal up a bit.

If your red buff is still up, go smite the main Krug (golems) and then go to red buff. It will reduce the damage you take by about 30-40% overall and is worth the time anyway.

Back whenever you're low on HP and can't recover anymore. Then buy based on First Back in the items section.

Start ganking at level 6:
Anything before that is pretty risky unless your enemy is out of position and quite low because you have no items to kill them with yet.

Pros:
-Strongest Q in the game
-Going untargetable as a dash effect will avoid everything except debuffs like ignite and Thornmail
-Reduced damage and healing in the same ability = 4 second tank
-True damage that scales with AD
-Few champions will ever be faster than you are
-One of the best wave clear mechanisms without AoE spells
-Gets out of hand really fast after 5 kills

Cons:
-Loses to hard CC => Stuns, snares, knockups, grabs
-Squishy and somewhat useless without items
-Not too strong pre LvL 6
-Will be targeted very easily
-Engaging without sight turns into suicide most times