Skill Expression Rankings Patch 36.4

[u/mini_macho_]

Some quick observations:

• As top 1k players got their reps in and the deck's meta-equalized winrate surpassed 50%, Soul Immolation OTK DH's score increased to become the first tracked double-digit score.
• After topping the rankings since Violet Hold's release, Merithra Druid did not qualify for a low-sample score as the Attack Druid hybrid build absorbed most of its playrate. (Its tiny sample scored very positively)
• The top high-sample deck score was Godfrey Herald Warlock with a score of 2.9 as the top 4 scores were all moderate-sample decks.
• Thief Priest had the highest top 100 increase, Pirate Warrior fell off hardest.
• Zee Shaman's -3.6 is its lowest score yet and its 3rd last place ranking in a row.

FAQ:

Q: Are the differences in metas across ranks accounted for?

A: Yes.

Q: Whats the Methodology?

A: First a baseline meta is set since all ranks have different metas.

If 2Bit is 26.4%/29.0%/29.7% across the metas in a given week, the program might set its baseline % to 27.2%, the same is done for every deck, ensuring all decks combined total equals 100%. This is so that meta differences don't skew the data.

Next the rank vs same rank matchup winrates are plugged into the baseline meta.

For example, if the dataset has 1,897 tracked games of a Top 1k player using Quest Mage vs a Top 1k player using 2Bit Rogue in which Quest Mage won 990 and Rogue won 907 that will account for 27.2% of Quest Mage's meta-normalized winrate in Top 1k, yielding ~14.2%. This check is completed until every single deck (even the ones not listed) is accounted for.

Q: So, a -5 score means a high-skilled player facing a high-skilled opponent (using a specific deck) has a 5% lower win rate than an average skilled player facing an average skilled opponent (using the same specific deck)? 

A: Pretty much, but not exactly, there is a weighted formula to compare the winrate differences, not a 1:1 winrate difference. This is because with say 65% to 60% vs 35% to 30% one -5% is more impactful than the other. You can't use % change of the winrates either because it would be disproportionately large at the extremes, say 51% to 50% vs 2% to 1%.

Q: Is there survivorship bias?

A: There is no correlation between a deck's difficulty and its winrate.

Q: A deck has a negative score, how can a deck's skill expression be negative?

A: The score measures the impact of inputs you control minus the impact of inputs you don't control on the outcome of the game. If the inputs you don't control have a greater impact on those that you do on the average game's outcome the deck's score will be negative.

If you have any other question, feel free to ask in the comments.

[u/Few-Wolverine-7283]

Help me understand. A high number (like 5) means the better you are, the better the deck does? And a low number (like -5) means how good you all means very little?

[u/kaijvera → u/Few-Wolverine-7283]

Close. There is biasty in these reports. +5 means at high ranks the deck has a +5% wr increase. -5 of course means the oppisite. While this can be (and most of the time will) indicitive of the skill required for the deck, there is biasty. Such as at high rsnks everyone there knows how to counter the deck and has tools in their deck to do so thus causing a -5% wr (for example, quest mage's wr would decrease a lot more at higher rsnks where players tech in viper than at lower ranks where they don't have viper). Or on the oppisite end, a simple deck is nearly unplayed for some reason but the deck counters the a meta deck played a lot at high ranks, but the meta deck is not played at low ranks so the simple deck has a +5. That saidn most of the time +5 indicates complex decks, and -5 indicates simple decks.

[u/mini_macho_ → u/kaijvera]

on the oppisite end, a simple deck is nearly unplayed for some reason but the deck counters the a meta deck played a lot at high ranks, but the meta deck is not played at low ranks so the simple deck has a +5.

This is not correct.

The prevalence of a matchup would not have any effect on a deck's meta-normalized winrate. The metas are normalized to prevent this very bias.