View Full Version : 539 defense and rounding fractions?

05-18-2009, 12:35 PM
How are fractional differences calculated, and a few miscellaneous questions:

1. If I have 539 defense and a .04% chance to be crit, is that rounded up to a 1% chance to be crit by a raid boss?

1b. (This came up because I was putting on frost resist gear for Hodir...out of curiosity how many pieces frost resist do you guys wear for 10-man?)

2. Same basic question but for me swinging at the mob...if the mob has a 6.5% chance to dodge and I have enough expertise for -6% chance to be dodged, will I be dodged 1 in 100 times or one in 200 times?


05-18-2009, 01:02 PM
1a) I believe the numbers are not rounded and it would be that 0.04% chance to be crit. I do not have the parsing data, so someone else may need to confirm on the actual math. I will say that personally even that small chance of being crit is too much for any Uldar encounter (esp Hodir), where 1 crit + any other attack could kill you before the healers have time to respond. I would set asside a piece of old gear that you can regem/enchant for +def so that you remain above the cap.

1b) I have done it with the 3 icebane peices with out a pally/shaman aura. I can say that Frozen blows does significantly more damage than his normal attacks and that is when the majority of raid damage is being done. To help Im planning on trying it with 3 Icebane + JC ring + tempered titansteel helm with FrR enchant. Overkill? yes probally but without the pally aura, and the extra room during normal phase, I might as well increase my survival while the healers are keeping the raid up.

2) see 1a

05-18-2009, 02:33 PM
rounding happens for things that are set numbers, for example, if you have say 9 defense rating, that'll give you 1 Defense Skill, not 1.05. and you won't see any benefit from it until it reaches 17 or 18 defense rating in which you'll have enough to get 2 defense skill. THAT is where rounding happens. IN the combat table however, it appears that it rounds up to the nearest hundredth so that .04% is still .04% chance.

05-18-2009, 04:38 PM
Ok, that answer makes sense, however...

When I read posts back in the day about crushing blows and the hit table, the combat result table was always presented as having 100 possible outcomes. Was that just for demonstration or has it been changed at some point to having 10,000 possible values instead of 100?

It seems like there would be big performance gains to have it at just 100.

Oh, and the other thing I keep forgettting. Is my chance to dodge a level 80 mob the same as my chance to dodge a level 83 mob? I downloaded the RatingBuster addon from a tankspot suggestion but I haven't noticed it.


P.S. The hit table would be simple but incredibly tedious to test.

05-18-2009, 04:41 PM
it was probably just for example. I've personally always used a 10,000 random generator whenever i gave examples, and for a computer, randoming between 100 and 10000 numbers is literally ns's of processing speed, it's minute. Testing has been done by satrina already and you can see that his testing shows accuracy even in small sets.

05-18-2009, 04:43 PM
Kazeyonoma are you a person or a cyborg constructed for the purpose of answering my questions on tankspot?

Either way, thanks!


05-18-2009, 04:48 PM
I'm just the only guy on right now is all. heh

05-19-2009, 05:34 AM
Lemme see if I can add some flavor without stepping on Kaze's (very knowledgeable) toes.

I have tanked Naxx, EoE, and Ulduar with 538-539 Def, not that I'm proud of it or would recommend it. The chance to be crit doesn't round off, and really even a 4 hour raid will see relatively so few swings from a boss that you won't get the big numbers to see accurate % values with that. I did it without ever getting crit in hours on hours of raids, but if I HAD gotten crit, AND it happened at the wrong time, it would've been totally on my head for not capping by any means necessary.

On Hodir, I personally do not use Frost resist, though I'm a DK with some beafy CDs and heavy healability. My warrior partner does wear a few pieces of frost resist loaded up with Def and we cover the group with a frost resist totem and that has made the healer's job much easier.

As I understand it, your chance to avoid is slightly reduced against a boss level mob. I'm not 100% that the reasoning is correct, but I'd imagine it is the functional difference in Defense's effect. Defense adds miss/dodge/parry/block (0.04 per def skill pt roughly) but defense acts relatively, so a level 80 mob is essentially lvl 400 weapon skill, while 83 is 415, so that trims your miss/dodge/block/parry functional rates on bosses ever so slightly (without factoring diminishing avoidance it'd be 0.6% off of each).

On the 10000 counters you see, I picked up a while back, I believe that the actual number generators in the system are base 10000 values, i.e. 100.00% = 0000, 45.53% = 4553, 0.04% = 0004. That's why you'll see some hit tables and the like interpreted that way. This is programmer tricks, messing with decimal points adds complexity and weight to software that can be more streamlined. Whole value tracking with 4 digits instead of say 5 digits with decimals and different scales starts to really add up when you think about how many checks the server is doing per second at peak operation.

05-19-2009, 08:17 AM
I just wanted to follow up with the Hodir fight.

Last night I tanked the encounter in full FrR gear (and remained defcapped), and I deffinately saw an increase in survivability during Frozen Blows. Yes I was getting hit alittle harder during the normal phase, but not dramatically.

Summary: FrR isnt needed, but it helps alot (even for a Blood DK like myself). I would recomend it to any tank in a progression group who hasnt seen Hodir. And tbh, the mats for the 4 peices of gear pales in comparision to the quality of loot that drops (I just got my Storm Edge last night).

05-19-2009, 08:49 AM
Ok, so if the combat table has fractional entries then it doesn't matter so much what my chance to dodge/parry an 83 is. I was concerned I was missing a whole percentage point because I was thinking it was rounded to the nearest 100. (e.g. 22.98% chance to dodge --> 22% when I could just toss a gem in.)

But if the combat table doesn't do that it doesn't really matter, sweet!


05-19-2009, 09:43 AM