Dodge chance when attacking mobs at level 60 is incorrect

[magey]

The formula for mob dodge chance in TBC should be 5% + (DefenseSkill - WeaponSkill) * 0.1%, unchanged from the vanilla/classic formula.

Dodge chance vs. +3 mob should be 5% + 15 * 0.1% = 6.5% but instead we're measuring ~6%:

Outcome	Chance	95% CI	Count
Miss	7.97%	±0.15%	9449
Dodge	5.93%	±0.13%	7036
Parry	14.06%	±0.20%	16676
Glance	23.81%	±0.24%	28237
Block	4.96%	±0.12%	5883
Crit	13.32%	±0.19%	15801
Hit	29.94%	±0.26%	35511

Dodge chance vs a same level mob should be 5% but instead we're measuring ~4%:

Outcome	Chance	95% CI	Count
Miss	23.80%	±0.37%	12017
Dodge	4.04%	±0.17%	2038
Parry	0.00%	±0.00%	0
Glance	6.07%	±0.21%	3064
Block	0.00%	±0.00%	0
Crit	18.38%	±0.34%	9281
Hit	47.72%	±0.44%	24101

See #1 for in-depth discussion and measurements.

[watchyoursixx]

#1 (comment)

It appears this dodge % being off is only for players, you can see in the comment for attack tables above that my pet had dodge % within the expected 6.5% against a +3 lvl target. However, in the same logs my melees were a good bit less dodges

Not sure what is causing this difference but there's clearly a difference here from what I can tell (between pets and players)

[watchyoursixx]

I did some more testing with pet and hunter at lvl 70. I believe magey mentioned in FC that there is some 50k~ data points that also point to this, but basically it appears that dodge vs 73 works as intended giving 6.5% dodge chance with 0 expertise (my previous test was actually with expertise so that's why player was lower dodge %)

From these logs I gathered the below data:
https://classic.warcraftlogs.com/reports/Mg9zrKZhaHxWw7nT#boss=-3&difficulty=0&type=damage-done&source=1
https://classic.warcraftlogs.com/reports/nfBCvyRLVaDwXt2N#boss=-3&difficulty=0&source=1&type=damage-done
https://classic.warcraftlogs.com/reports/JKkv4YHByjTC2n8a#boss=-3&difficulty=0&source=1&type=damage-done

Player - 70 vs 73, 11.26% sheet crit, no exp, no hit

Result	Chance	95% CI	Count
Parry	14.58%	0.55%	2276
Miss	7.86%	0.42%	1226
Dodge	6.25%	0.38%	975
Glance	24.44%	0.67%	3814
Crit	6.64%	0.39%	1037
Blocked Hit	4.98%	0.34%	778
Hit	35.25%	0.75%	5501

Pet - 70 vs 73, 14.99% sheet crit, no hit

Result	Chance	95% CI	Count
Parry	14.05%	0.50%	2610
Miss	8.07%	0.39%	1500
Dodge	6.68%	0.36%	1241
Glance	24.61%	0.62%	4572
Crit	10.08%	0.43%	1872
Blocked Hit	5.26%	0.32%	977
Hit	31.24%	0.67%	5804

Hope this helps.

[magey]

As can be seen here we did another round of tests, but this time 70 vs 73 (as opposed to 60 vs 63 the last time). Across 105K attacks we got:

Outcome	Chance	95% CI	Count
Miss	7.95%	±0.16%	8379
Dodge	6.48%	±0.15%	6826
Parry	14.12%	±0.21%	14887
Glance	24.22%	±0.26%	25528
Block	5.06%	±0.13%	5337
Crit	14.53%	±0.21%	15315
Hit	27.64%	±0.27%	29133

Which leads me to believe the dodge formula problem is specific to lower level mobs/players.

[magey]

And confirming that 70 vs 70 (350 vs 350) also has the correct dodge chance over 51K attacks:

Outcome	Chance	95% CI	Count
Miss	5.04%	±0.19%	2582
Dodge	4.96%	±0.19%	2540
Parry	5.09%	±0.19%	2604
Glance	6.01%	±0.21%	3075
Block	4.84%	±0.19%	2477
Crit	18.57%	±0.34%	9508
Hit	55.50%	±0.43%	28417

[Aggrend]

The combat table is different in 2.X at level 60 than it is at 70. It's unclear if this was actually intended or a quirk of how it was written, but the engineers confirmed this is correct and accurate in our reference and BCC clients. Dodge being slightly lower at 60 is Not A Bug.

Have fun in pre-patch!