Most people consider that Master Yi is a champion that should not be played in high elo, ad Yi melt during team fight, tank Yi got no dmg, and Ap Yi lack of burst and is only good when the enemy team has no cc.
I dont no about the ad Yi and tanky Yi, but there is one thing im sure about, Ap Yi could definitely be played in high elo.
Even though im still a player in elo hell, but i have already played 900+ranked games ( played ranked since 30, fall into 800 elo at the begin and carried myself out from that terrible place ) and I played almost every ap champions, watch a lot streams and I do understand the advantage and disadvantage of most ap champions.
Those days I started to play Ap Yi in ranked, and amazingly i found out that Ap Yi is much much better than most people though. After a long time practise, I realize Ap Yi is a pretty good Ap champion, he has some advantage that other ap champions dont have.
The advantage and disadvantage of Ap Yi:
1.Ap Yi is an amazing farmer, he can get more than 200cs in 20 mins if he focus in farming. No other apc can farm as well as him, he is the number 1 farmer
2.No one can kill Yi during lane time because he has amazing substain.
3.Ap Yi deals great aoe damage during team fight.
4.Hard to be ganked when he hit lvl 6
5.He is good at chasing low hp enemy
1.Has no stun,which made jungler (on Yi side) doesnt want to gank mid
2.His Q is not reliable, it wont hit enemy every time
3.Ap Yi is only for organized and experienced players
Unlike wuht most people believe, dmg is not a problem for Ap Yi, and he is also good when enemy has a lot cc, here is some tips i gonna to show u how to be a good Ap Yi :
1.(when game start) at the begin of the game u buy boot and 3 pots, u can also buy boot pot and ward since u have w, but i prefer buying 3 pots. Ap Master Yi wont help jungler leash because u might take his cs when u do that, what u gonna do is going to steal enemy wrath, or take ur own wrath if ur jungler gonna gank or invade after blue. Always check the bush behind red buff, make sure enemy dont see u, give up immediately if some one is guarding there. U use ur q to steal wrath, use ur pots when u get low, dont worry about hp, u are impossible to kill when u get lvl4. Always learn q first, w seond, e when enemy cant do much damage on u so u dont need to use ur w and e will make easy for u to get cs and take wrath.
2.(how to lane) u must be carefull dont be killed at early lvl, but i dont think u need to worry about that if u are an experienced player, most ap champion dont have burst at first 3 lvl, u auto attack to get cs and q when there is few minions and enemy is close to them, w when u are low. Pay attention whether the enemy has stun or not, dont worry if the lane is pushed, u got flash, use it when enemy jungler gank u, take ur own wrath and b if u lane is still pushed. Usually u are lvl 4 or 5 at this time. The first item u need is Kage's Lucky pick, Ap Yi depend on gold and u need the Deathfire late game, at same time u can also buy a Doran ring and use all the left gold to buy wards.(ward>doran when u have no gold) Ward river when u are back to lane and ward enemy wrath. Now wuht u need do is keep pushing ur lane and keep steal enemy wrath and take ur own wrath or wolves when ur jungler is ganking other lanes, ur Q might not kill every minions, but 1 or 2 cs is not important. When u are low use ur w under u tower. And here is the funny part when u hit enemymid few times they will be low and dont want to get close to his minions. When this happens stop pushing, start auto attack to get cs, q only when he come to his minion to get cs. U gonna out farm the enemy when u do this.
3.(when to gank) well, usually Ap Yi wont gank, becasue u have no cc..u can only kill them when they are low enough and if they dont buy wards and dont call mia ( however this do happen sometimes) when enemy mid is ganking u need to call mia but dont follow if u are sure they not gonna to dive, remember u are winning ur lane, enemy wont have a lot farms because ur Q, that mean his damage wont be a much big deal. ( if he build dmg only, u can easy bring him low during lane time, and if he b he lost cs) Wuht u need to do is pushing mid hard and get that turret, u are master Yi man, even u are building ap u still have some nice ad dmg.
4.(Early team fight) okay here come the team fight, usually it starts near dragon. Because u are farming greatly, u must already got large rod and lvl 2 boot already, at this time u need have at least 30 more cs than enemy mid. U dont go in first, but if u feel confident that u wont get stunned u can Q enemy tank who stand in front of their team to make some aoe dmg when team fight just start and run away immediately when q is over(use flash if u have to). Now u need to wait, because u already deal some aoe, enemy team wont be full. At that time most chapion wont able to survive 3 Qs from a well farmed Ap Yi ( Tank might need 4 Q to kill, with magic shield 5Q). All u team need do to do is to deal the same dmg u deals to ONE of the enemy who is squishy, if u team cant do that, good luck its elo hell. But when u team is okay to do that and bring one enemy low enough for u to kill, its ur showing time, ulti and q, get kill Q again, now u already deals 3 Q to all the enemies, if they are not fed, they must be very low or even died now, keep Q if u can, if u cant, u must believe u team could finish the enemies who has only few hp...its so easy to get triple even quadra kill in early game with Ap Yi, and u are not KS!!! U deal most dmg, however in late game when u team is also fed, they might steal ur kills
5.(okay, here come the late game) Now u must have the Cap, deathfire or(and) lich bane
u can simply kill enemy ad and ap carry in one combo if they dont build hp, if they do build mr and hp, that means they deal less dmg, u make u team more easy to survive, u basically doing same thing like early game if thats the case
Some other tips:
1.i use ap rune, magic regain rune and mr rune so that i dont get killed in a combo by enemy mid, if enemy use ulti and ignite and havent kill u, use ur w, u will be a man again, and they cant do anything to u in a while
2.when ur bot or top is lossing, dont gank!!!u are wasting ur time to do that, i loss mid only once as ap yi, and thats because i have to help bot when they got destroyed ( die 5 times in 5 mins) people will call mia and will buy ward, ganking just give fed enemy chance to double kill. When U team failed, u are the only one able to safe the world, forget u team, keep farming, becoming a superman.
3.dont just q in enemy team during teamfight and w like a boss. u are apc not tank. NOOBs who doing that make people thinking Ap Yi is only good when enemy has no cc... every champion is good when enemy has no cc!!!
4.tank turret and dragon for ur team because u are master yi u are a man,when no one can stun u, u can w like a boss
5.when u get caught and u team come as soon as possible and enemies already use their stuns on u to bring u hp to a very low lvl, use ur w . Too many times when enemies were keeping focus on me after they used their stuns...my team finish them easily since they insist finish me first...ignite wont be a big deal, when u have 400 ap, no one can kill without stun
6. be nice to ur team even they are not very pro, its a game of 5 person, Just like any other ap carry, Ap Yi needs a team
here is a video about Ap Yi in a very high lvl battle, clg.na vs ig
ap yi carried his team, even through he didnt get a lot kill in late game, but because the enemies are keeping focus on him, use all ulti on him, which give his team chance to deal dmg and finally make an ace. ( clg has to focus him because he is so farmed and so hurt....)
Compare with other Ap champions, Ap Yi is not even close to bad, its just..too many noo(the letter between a and c)..i mean ..players who is not so organized are using him which making people think he is bad...
I hope people will like my "guide" using my tips and carry their team with ap master yi, tell the world, Ap Yi in ranked is not a troll pick...
(And u can see me match history with ap yi)