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According to stats taken from Kripp and Hafu's streams, not only is Blizzard's stated KFT offering bonus incorrect (~1.5x instead of 2x), but the class card offering bonus is incorrect (~1.2x instead of 2x).

Note 1: Last week, I made a post saying Blizzard had been lying about the micro-adjustment system. I have repeatedly apologized for using the word lie, as I had not considered I misinterpreted their statements. With that said, my math was correct, and confirmed by Mike Donais, that there had been no micro-adjustments in KFT. My math has been correct in each of the previous incidents I've made these posts. What I'm saying is, think of me what you will, trust the math.

Note 2: I have been in contact with Iksar about this. The last contact was Friday afternoon where Iksar asked me to send him some cards to compare so he could run it through the Blizzard editor to see how they turn up, and I sent them to him, and he hasn't gotten back yet. He has told me he doesn't mind if I post this, so now that I have everything together, and I'm mostly confident my math lines up, I'm making this post. FWIW: I think Iskar is skeptical about all this, but that is more likely because I did a shit job of explaining my initial stats to him, and I've been working to simplify my explanations so people can follow my logic.

Note 3: This is a stats post, it's going to be long, there is no way for it to not be long, I apologize. Title is the TLDR, I need to explain my methodology thoroughly in case I screwed up somewhere along the way so someone can point it out. FWIW: I'm also leaving out a lot of extra stats I've gathered in the interest of brevity and to make my point as simple as possible.

• 1: Introduction: What are Offering Bonuses, and where do my stats come from.

In Arena, certain cards are offered in drafts more than other kinds of card. Class minions have a 2x bonus, Class spells/weapons have a 3.5x bonus (2 * 1.75 = 3.5), and Basic/Classic neutral minions have a .5x reduction. In addition, KFT cards should have a 2x bonus, the same as when Ungoro was release. In total, you get 7 different sets of offering rates in Arena: KFT Spells/weapons (7x), normal spells/weapons (3.5x), KFT Class minions (4x), class minions (2x), KFT Neutrals (2x), Neutrals (1x), and Basic/Classic neutrals (.5x). This is all data taken directly from Blizzard and how it was interpreted, correctly, for the release of Ungoro.

ELI5: Offering Bonuses: Imagine you have 10 pieces of paper, numbered 1-10, and put them into a hat. You have a 1/10 chance to draw any number. Now, imagine you put 2 more pieces of paper in the hat, numbered 1 and 2. 1 and 2 would have a 2x offering bonus. Your chances to draw a 1 would now be 2/12, while your chances to draw a 4 would be 1/12. This is how Discover works, where class cards have a 4x offering bonus compared to Neutral cards.

Lets say, I know 1 and 2 have an offering bonus, but I don't know what it is. The way I am calculating it is looking at the ratio between two different sets, in this case, 1/2 vs. 3-10. As in the hat there are 4 pieces of paper with a 1/2 and 8 pieces of paper with a 3-10, the ratio between these is 1:2. If I were to pull a random number out of a hat 99 times, 33 of those times should be a 1/2, and 66 should be 3-10, as 33:66 = 1:2 ratio.

Now, lets say instead of 33/66, I end up pulling 20 1/2s and 79 3-10s, for about a 1:4 ratio. And lets say, I did this again, and came up with the same results again, give or take. And someone told me that this ratio should be a 1:2 ratio. Would you believe them? This is the point I'm at right now with Blizzard.

My stats: I initially wanted to use HSreplay, but that is pick data, and its not nearly reliable enough to confirm these numbers (although it certainly supports my findings). So what I decided to do was track every Hafu draft from October, and jot down every time a card from one of the different offering rate groups (KFT spells, non-KFT spells, etc). To get a second opinion, I then took Kripp's publicly-available Hearth Arena data and tracked all of his KFT runs from the 2nd week of KFT on for Druid, Paladin, and Rogue (to compare with/add to Hafu's numbers). I initially tracked all of the rarities before settling on just Common, as it has the largest sample size and presumably, if an issue is effecting commons, it should effect all rarities. I did not count the "Synergy Picks," the first two picks of the draft, as those are from a different set of offered cards. Also, for Kripp, I didn't count when he was too fast for the HA client and it only gave the card he picked as I felt that would skew the data slightly to "good" cards. I acknowledge I may have made errors in bookkeeping, but those errors should not have a major impact on the overall results.

Before anyone asks, yes, I did ask Heartharena for stats, but he hasn't responded to my message, so I figure he's busy with his real job. If at some point he could check in the future to confirm my findings, it's be appreciated.

Why I chose Hafu/Kripp: I chose Hafu because she drafts fast so I felt it'd be quicker to watch her than other streamers. It was not quick. I chose Kripp cause his stuff was online and much easier to jot down, and thankfully it was, 1/4 of the same time it took to write down Hafu's stats.

• 2: The KFT bonus is approximately 1.5x instead of 2x

In the Arena right now, there are 22 KFT Neutral Commons, 74 Neutral Commons, and 83 Neutral Basic/Classic cards. Assuming a 2x ratio for KFT cards, that would mean the ratio for these cards should be 44:74:41.5, or simplified to a 1:1.68:.943 ratio. Assuming a 1.5 ratio, the ratio between these cards should be 33:74:41.5, or 1:2.24:1.26.

For the largest sample size, I added together all the KFT neutrals, Neutrals, and Basic/Classic (B/C from now on) neutrals, from Kripp and Hafu's numbers. This gave me a result of 566 KFT, 1161 Neutral, and 715 B/C. This creates a ratio of 1:2.05:1.26. The ratio between KFT and B/C is exactly the same as the expected 1.5x ratio. The ratio between KFT and Neutral is, while not nearly as accurate, clearly favors the 1.5 ratio rather than the 2x ratio. In either case, these ratios very clearly point out that the Offering Bonus that Blizzard says is in place (2x) is not in place. 1.5 is my guess, and it could be higher, but from going through 15 different iterations, the chances that both Kripp and Hafu are this far away from the expected ratio are microscopic.

To add validity to this claim, lets use HSreplay data. The most popular KFT class epic is Ultimate Infestation with about .54 appearing/deck. The most popular non-KFT class epic is Vilespine Slayer with about .2/deck. After adjusting for the spell bonus, you get .35 per deck. (.2 * 1.75 = .35) .54/.35 = 1.54, the expected KFT bonus. To put this in perspective: If the KFT bonus were 2x, you'd expect .7 class spells/deck. This would mean that 23% of the time, people are passing UIs if they see them in drafts. That's not happening. Again, data is inaccurate enough to not determine an actual number, but accurate enough to point out there's no possibility of it being 2x.

Conclusion: The KFT bonus is not 2x. I'm running under an even-number assumption of 1.5x, but the numbers indicate it could be higher, possibly between 1.5-1.6x.

• 3: The Class Offering Rate bonus is 1.2x, not 2x.

Note: Because of the uncertainty of the KFT bonus, its not fair to compare KFT cards or use ratios from KFT cards as small errors there can compound. So, for the sake of simplicity sake, I'm only going to compare Class minions (2x) to Neutrals (1x). Also, because these are individual class stats, the sample size is admittedly small, so there is a lot more room for variance compared to the Neutral cards. However, again, my math will show that the offering bonus is nowhere near 2x, and real close to 1x, which I was able to pin down around 1.2x.

I have to go class by class here as they all have different individual offering rates. Starting with Rogue, the largest sample size. There are 8 Rogue class minions and 74 neutral cards. Under a 2x offering bonus, 8 * 2 = 16, so that'd be a 16:74 Ratio, or a 1:4.625 ratio. At a 1.2x bonus, 8 * 1.2 = 9.6, so we would end up with a 9.6:74 Ratio, or a 1:7.71 ratio. From the combined Kripp/Hafu stats, I have 46 Rogue Minions and 359 neutrals giving a 46:359 ratio, or 1:7.8. Notice the massive disparity from the 2x ratio. Sample size, sure, this large a sample size is not impacting the ratios that much.

But, hey, that's one class. Why don't we take a look at Druid. 9 minions for Druid, at 2x = 18:74, or 1:4.11. At 1.2x, 10.8:74, or 6.85. My numbers are 38 Druid minions, and 269 neutrals, leading to 38:269, or 1:7.08. Again, nowhere near close to 2x.

But maybe that's just two classes, why not Paladin? Only 6 Pally minions, so at 2x, 12:74, or 1:6.17, while at 1.2x, 7.2:74, or 1:10.28. I came up with 19 class minions and 208 neutrals (Hafu doesn't like Paladin), leading to a 19:208, or 1:10.95 ratio. A whopping massive .67 difference, dwarfing the .09 from Rogues or the .23 from Druid........ and no where near the expected 2x ratio.

But maybe, just maybe, I'm making all this publicly available shit up. It'd be nice to have something independent from my random scribbles in my notebook. TO HSREPLAY.NET! Abyssal Enforcer is the most popular class card, sitting at .163/deck. However, it also has a 50% reduction, so it should be at .326/deck, to set the standard of what a class minion's offering rate should be. Tar Creeper, using its Warlock takes is the most popular non-KFT neutral, showing up in .252/deck. A 2x class offering rate would mean that class cards should appear .504/deck. Meaning, 35% of the time, if someone is offered an Abyssal Enforcer, they are skipping this. And that's assuming Tar Creeper gets picked 100% of the time. That is not happening. A person who was born mentally retarded, deaf, and mute, who is beset with Alzheimers and Dementia, could pick up Hearthstone, and know enough to not skip Abyssal 35% of the time. There is no universe where Hearthsone exists, where someone would skip out on Abyssal 35% of the time. If, however, the offering rate was 1.2x, .252 * 1.2 = .302. Which means Abyssal is more popular and picked more than Tar Creeper, which sometimes gets skipped. Which means all is in fact right with the world.

Conclusion: Shockingly, these stats are much more accurate than the KFT stats among a smaller sample size, and much more consistent. Unlike the KFT bonus where I think its 1.5 as a floor and probably 1.6 as a ceiling, I'm certain that the Class bonus is only 1.2x, and not 2x.

• 4: Conclusion: How this could've happened, and my personal thoughts about it

Clearly, the stated offering bonuses are not the same as in game. I've come to reasonable conclusions about this, and I'm confident in my data. If someone is able to point out where my data is incorrect, please do so, I'm more than willing to admit my faults. But to me, there are 4 possibilities for why the numbers don't match:

1: Sample size/micro-adjustments/any number of math issues: Perhaps I screwed up the math somewhere. I doubt it. There might be minor math errors in here, but the fact I've been able to replicate this data over numerous data sets (combined for brevity) makes me confident that my math is correct, and that the influences any of anything minor like micro-adjustments or removed cards are, in fact, minor.

2: I misinterpreted Blizzard. What happened last time. These are the rules listed on their site. Perhaps the bonuses are additive instead of multiplicative. Perhaps they meant something different than what their rules state. The rules worked in Ungoro, and don't work here, so I assume my interpretation is correct. If I really misinterpreted the rules, they need to be made simpler, cause I don't know how else to interpret this.

3: Blizzard changed the offering rates and did not inform the community/Iksar. This is something Blizzard would never do....... except they did it 4 months ago with the weapon offering rate changes. By the way, in spite of a #1 spot on /r/hearthstone and being informed via twitter and in thread, there were to my knowledge no Dev comments acknowledging this, much less an apology, for implementing these changes in 8.2 and not informing the community until 8.4. Iksar not knowing this makes me think this is not possible, but I still wouldn't be shocked.

4: This was an accident in the editor that changed the rates and it has went unnoticed for 2 and a half months. 2x to 1.2 makes me think this is possible (decimal point error), and the KFT rates being close to the Ungoro rates make me think this is possible as well. Iksar to me said that the Internal Arena Editor has the Latest Expansion rate at 2.0. From the stats I pulled plus the HSreplay stats, this is clearly not the case. This to me is the most likely scenario. As the HSreplay stats have shown no change since KFT, that means that these rates have likely been in place since KFT released. And its sad and frustrating that after 2 and a half months, and after having been informed that the KFT rates were inaccurate, that it was not acknowledged or fixed (Iksar's checking aside, which I want to thank him for putting up with me a bit terse and my numbers that make sense to no one but me). And that a massive change to class offering rates went unnoticed for 2 and a half months.

Personally, I'm frustrated with Blizzard. I have arm issues, and typing this many words to make a point that should be easily verifiable is not good for my arms. I spent probably 20+ hours in the last week pulling together data and calculating and trying to figure out how to simplify everything to be as easy to digest for people. This is not my job, and it shouldn't be my job. These are the absolute basics of Arena, the bare-minimum, and now people aren't going to trust Blizzard can handle that right for the next 6 months at least. If you wonder why I get frustrated enough that I call Blizzard liars, if you wonder why ADWCTA who benefits from a positive relationship with Blizzard is willing to compare the handling of Arena to someone driving a car under the influence, this is why. This is, by the way, the abbreviated rant, and this is me being polite to Blizzardl

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