Original Post — Direct link

TL;DR I trained a machine learning model to figure out which champions are banned more than their performance and popularity deserves. The top 5 most over-banned/hated champions are Samira, Darius, Morgana, Zed, and Yone. The bottom 5 are Jhin, Ezreal, Ashe, Kaisa, and Thresh.

The process:

  • Data taken is for Plat+, global player-base, patch 10.21. Data is collected from lolalytics.com.
  • For each champion, we record their pick-rate, ban-rate, and win-rate.
  • We train a multivariate linear regression model with the data. The model is trained such that it tries to predict the ban-rate as a function of the win-rate and play-rate of a champion.
    • Actually, ban-rate and play-rate are log'd first, then put into the regression model.
  • For each champion, the model will predict a ban-rate based on their win/play rates. We take the difference between the predict ban-rate and the actual ban-rate. If the actual ban-rate is significantly higher, it indicates that a champion is being banned more than their stats deserve.
    • I admit this method has its weaknesses; i.e. it assumes that the relationship between the different variables are in fact linear. Upon inspection, ban-rate does appear to be a linear function of pick-rate. However, it is difficult to say exactly whether ban-rate is a linear function of win-rate, since the relationship between the two is surprisingly weak to begin with.
    • Another concern is whether the win-rate and play-rate are correlated with each other, since you ideally want independent features for multivariate regression. Win-rate and play-rate are in fact not correlated with each other (p-value=0.92).

Champions towards the top of the list are widely hated, with ban-rates significantly higher than their play-rate and win-rates would justify. Champions at the bottom are they opposite: They tend to be popular, yet have ban-rates much lower than normal for their pick-rate and win-rate. Champions at the middle aren't really liked or disliked; people are generally ambivalent about them.

Below is the complete list of ([actual ban rate] - [predicted ban rate]) values for each champion.

 Samira:63.05
 Darius:33.33
 Morgana:29.93
 Zed:29.23
 Yone:23.49
 Yasuo:21.41
 Evelynn:20.76
 Hecarim:19.83
 Akali:19.35
 Pantheon:16.32
 Kassadin:16.17
 Yuumi:13.39
 Lillia:10.77
 Master Yi:9.90
 Renekton:8.57
 Lulu:8.21
 Vladimir:8.01
 Irelia:7.41
 Lucian:7.26
 Blitzcrank:7.19
 Fizz:6.98
 Fiora:6.08
 Karthus:6.04
 Nautilus:6.00
 Ekko:5.96
 Graves:5.83
 Caitlyn:5.01
 Elise:4.92
 Jax:4.79
 LeBlanc:4.59
 Sylas:3.96
 Rammus:3.83
 Leona:3.67
 Shaco:3.65
 Mordekaiser:3.25
 Kha'Zix:3.00
 Fiddlesticks:2.95
 Rengar:2.64
 Katarina:2.40
 Sett:2.31
 Malphite:2.26
 Garen:2.25
 Illaoi:2.11
 Pyke:1.96
 Zoe:1.95
 Malzahar:1.90
 Volibear:1.65
 Olaf:1.64
 Tryndamere:1.64
 Nidalee:1.62
 Cassiopeia:1.53
 Quinn:1.41
 Diana:1.29
 Teemo:1.24
 Draven:1.04
 Nasus:0.97
 Talon:0.93
 Rek'Sai:0.85
 Urgot:0.81
 Nocturne:0.75
 Zac:0.75
 Swain:0.73
 Vayne:0.62
 Brand:0.61
 Kled:0.42
 Heimerdinger:0.26
 Yorick:0.23
 Tahm Kench:0.23
 Kayn:0.23
 Aatrox:0.21
 Dr. Mundo:0.18
 Nunu:0.16
 Qiyana:0.14
 Jayce:0.13
 Xerath:0.09
 Gangplank:0.08
 Trundle:0.07
 Poppy:0.03
 Anivia:0.03
 Taliyah:0.02
 Lissandra:0.01
 Rumble:0.00
 Syndra:-0.01
 Ivern:-0.03
 Neeko:-0.04
 Azir:-0.06
 Aurelion Sol:-0.08
 Maokai:-0.09
 Cho'Gath:-0.09
 Vel'Koz:-0.10
 Kog'Maw:-0.11
 Taric:-0.11
 Corki:-0.12
 Veigar:-0.12
 Zyra:-0.14
 Shyvana:-0.14
 Varus:-0.15
 Kennen:-0.15
 Wukong:-0.16
 Skarner:-0.17
 Gnar:-0.17
 Kalista:-0.18
 Sejuani:-0.20
 Ziggs:-0.20
 Udyr:-0.24
 Amumu:-0.31
 Gragas:-0.34
 Viktor:-0.34
 Annie:-0.35
 Galio:-0.40
 Zilean:-0.42
 Warwick:-0.43
 Aphelios:-0.45
 Xin Zhao:-0.45
 Sivir:-0.51
 Singed:-0.52
 Xayah:-0.53
 Senna:-0.57
 Braum:-0.61
 Kayle:-0.64
 Ryze:-0.64
 Sona:-0.71
 Camille:-0.79
 Jarvan IV:-0.82
 Shen:-0.94
 Tristana:-1.00
 Kindred:-1.03
 Twitch:-1.06
 Sion:-1.07
 Riven:-1.11
 Ornn:-1.36
 Vi:-1.38
 Twisted Fate:-1.71
 Soraka:-2.15
 Rakan:-2.29
 Ahri:-2.31
 Karma:-2.44
 Alistar:-2.64
 Nami:-2.71
 Lux:-2.96
 Bard:-3.00
 Jinx:-3.35
 Janna:-4.85
 Lee Sin:-5.79
 Miss Fortune:-5.93
 Orianna:-6.12
 Thresh:-9.45
 Kai'Sa:-10.87
 Ashe:-17.44
 Ezreal:-25.13
 Jhin:-35.18
External link →
over 3 years ago - /u/PhreakRiot - Direct link

There are two issues I have with this: First, there is a "best ban" and your team must use distinct bans, meaning there are five "best bans." So while your model may say that Samira should be banned in 30% of games, she in fact should be banned in every game if players are banning optimally.

According to Lolalytics, the 5 best (play rate * win rate) bans in patch 10.21 are Samira, Zed, Jhin, Hecarim, and Lulu.

So seeing Samira and Zed in your list as disproportionately banned, despite being the two best bans in League of Legends (and, almost more importantly, the #1 Bot Lane and #1 Mid Lane bans), makes this methodology feel flawed.

The second issue is that sub-50% win rates are champions you want to see in your games because you're likely to beat them. This is why it feels odd that Jhin and Ezreal are next to each other. Jhin is indeed left up more often than his power level suggests. However, Ezreal shouldn't be banned: He doesn't win very often and he's really popular. I welcome my Ezreal lane opponents.

I still think it's super interesting and a lot of this is really quite usable. But I think reconsidering what exactly you're measuring with winrate and maybe viewing sub-50 as a negative may make this better.

over 3 years ago - /u/PhreakRiot - Direct link

Originally posted by Pozay

Is it really though? I feel like there is more to bans than just pick rate and win rate. For example, if you ban lulu but janna is the 6th best champions, you don't win much, if you instead ban darius and a bruiser champion which is 7th only leaving bad bruisers, you force bruiser players into bad position. My example wasnt that great but I think you get what I'm saying

There's definitely something interesting there. "If my lane opponent would pick Samira, do they just pick Jhin, who's similarly powerful?" There's a more advanced model out there somewhere, yeah.

However, the opposite is true, too. If you ban Thresh, what if they pick a stronger champion instead?

over 3 years ago - /u/PhreakRiot - Direct link

Originally posted by Fencing_fenrir

The second issue is that sub-50% win rates are champions you want to see in your games because you're likely to beat them

Wasn't ye olde Kassadin of S3 below a 50% win rate when he got through the 1% of banning phases?

Yeah. People typically ban (somewhat fairly) for frustration instead of power.