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A guide to miss chance - auto-aim, player movement, and strength values

Goldmansbarn

New member
Theory and Findings

For any player that does not use auto-aim, for AoE's, or any player using melee, this guide will be irrelevant, miss chance does not apply. However, it is often claimed that when a player uses auto-aim they have a 5% miss chance for ranged weapons. For each 100 strength value, miss chance is reduced by 1% up to a total of 4% (400 strength) which will leave the player with a 1% innate miss chance that cannot be further reduced or negated whilst using auto aim.

This understanding of miss chance is wrong and, in many ways, incomplete. Most importantly, it fails to capture the relationship between miss chance and player movement. What it gets right, I believe, is that 100 strength roughly reduces miss chance by 1%. Although a defending players dodge will reduce the value of strength. The aim of this guide is to hopefully give the community a better understanding of how movement and strength impact auto-aim miss chance.

ScrubyMcBubble should be credited for finding the relevant code and sharing it, I would like to personally thank him for bringing it to my attention and making this guide possible. Essentially the code claims the following:

Ranged Auto-aim miss chance = +5%
Player (attacker) movement penalty = +5%
Defender movement penalty = +3%


Players using manual aim also gain +3% to critical chance.

There is no mention in the code of a 1% innate miss or a 1% miss chance that cannot be reduced or eliminated. Further, it appears that the three above miss chance penalties stack. There are essentially 4 kinds of miss chance. 1. Miss chance with both players moving, 2. Miss chance with the attacking player moving and defending player stationary, 3. Miss chance with the attacking player stationary and defending player moving, and 4. Miss chance with both players stationary. The movement penalties are contingent upon using auto-aim. Here are some examples of how this may look:

Example 1:
If you are using auto aim, you will have a +5% penalty, if you (the player) is moving add another +5% (10% total), and you are attacking the defender who is also moving +3% for a total of +13% miss chance penalty with a strength value of 0.

Example 2:
If you are using auto aim, you will have a +5% penalty, if you (the player) is stationary, then, there is no penalty, and you are attacking the defender who is moving for a +3% penalty. This will total at +8% chance to miss with a strength value of 0.

Example 3:
If you are using auto aim, then, +5% penalty, you are moving +5% penalty, enemy is moving +3% penalty, and you have 1300 strength. Then, you will never miss a shot. 1300 strength reduces the 13% miss chance to 0% miss chance.

Essentially, player movements will increase chance to miss. Your character’s movement is mostly in your control; therefore, a significant percentage of miss chance can be influenced by how you move. However, for the most part, the enemy players movement is not in your control and they can increase your miss chance simply by moving. Also, the movement associated with a player dodging an attack counts as movement which will increase miss chance. Roots for yourself and others should now be considered a means by which you can reduce your miss chance if you lack sufficient strength value. Further, the 1% innate miss chance that cannot be countered, is a myth. You can have 0% miss chance, thus, landing every shot unless parried or dodged.

Below is a chart that I have used to predict the relationship between movement, miss chance, and strength value given what is written in the code.

Chart1.png


(AA = Auto aim. PM = Player moving. PS = Player stationary. DM = Defender moving. DS = Defender stationary)

Even though the chart above makes sense given the code, it would not have been enough to convince me that this is the real relationship between miss chance, player movement, and strength value. Scruby has informed me that there are various pieces of code in the game that are not in-use, that are present in the files, but were either part of an older version of the game or were planned for future use. Just because the code appears to say the game is a particular way does not mean that it is. Also, my interpretation of the code could have been wrong, hence, worth testing.

Despite me saying all of this, as far as I can tell, the above chart is roughly correct. However, there is some difficulty with measuring miss chance. For those of you that do not care about these difficulties, as well as any further reasoning, justification and minor findings, you need not read past this point and can simply use the above chart for future reference with respect to miss chance. However, I would strongly recommend you read the 'Expected miss chance vs observed miss chance' section to better understand how a defenders dodge can impact an attackers miss chance.


Reasoning and Justification

The predicted miss chance chart you see above was partially the result of gathering data (chat-logger) on players attacking each other whilst moving and not moving using auto-aim with samples of shots fired ranging between 2,000-7,000 shots at strength values in 100 increments. A pattern started to emerge in these samples that was, at times, similar to the above chart. However, some of the results varied heavily and I did not find these samples to be entirely reliable. It was the conjunction of these preliminary samples and the +13% miss chance interpretation that led me to create the above chart as it was what made sense given the data I was reading and what was in the code.

As I said, I found some of these results to be unreliable. I believe this is because 2,000-7,000 shots fired for sample sizes are too small for testing miss chance accurately. Consequently, I increased the sample sizes to between 32,000-38,000 shots fired in order to get more reliable data and see how closely it would match the predicted miss chance as outlined in the chart above.

Below is a chart that shows the Player (attacker) using auto aim whilst moving against a defender who is also moving. The blue line below is the same blue line in the prediction chart above, it represents predicted miss chance in this context (AA+PM+DM). The grey, orange, and yellow lines represent three different players attacking each other P1 attacking P2, P2 attacking P3, and P3 attacking P2. Each dot on these lines is a sample ranging from 32,000-38,000 shots. Essentially, three samples for each strength value from 200 to 1200 in increments of 100 for a total of 36 samples. This was carried out to show potential variation between these larger samples at each of the selected strength values and their differences when compared to predicted miss chance.

The only exception to the above sample sizes are the two at 1300 strength. These are each 2,700 shots fired which is more than sufficient for demonstrating that at 1300 strength there is a 0% miss chance, there is not a single recorded miss in these samples.

Observed.png


In general, the chart shows a slight trend in that the lower miss chance percentages are closer to what is predicted. There is only a single sample that went above the predicted miss chance indicated by the blue line. This occurs at the 1000 strength value mark, where predicted miss chance is 3% and one of the samples goes above at 3.1%.

Interpreting these results has been difficult. The next section will explore the differences between expected miss chance and the trends in my data. This second chart was purely for testing purposes aimed to confirm the 13% interpretation. In practice, no one is going to be fighting for 5-6 hours straight hitting their opponents with 32,000-38,000 shots.

I decided to do the same experiment above, 3 players each attacking a defender, all moving whilst using auto-aim. The difference in the chart below is the sample sizes, these samples are roughly 5 minutes long and are between 510-550 shots fired. The purpose here is to more realistically examine what your miss chance may look like given these strength values and player movements.

chart3.png


The results here are not surprising given the small sample sizes, you can see that these results are less consistent and very RNG. While you shouldn’t take any of these samples as accurate representations of what your fights will look like, this is the sort of variability you should expect given these strength values when both players are moving and using auto-aim. With that said, these smaller samples are consistent with the 13% miss chance view. The purpose here is to demonstrate that even if you have 600 strength, you may experience a miss chance of 4.2% with good rolls, 8.4%, or even higher with bad rolls. It is also worth noting that the value of strength, in practice, is a bit less than 100 = -1% miss chance due to the overriding effects of dodge. This will be discussed in the next section.


Expected miss chance vs observed miss chance

LemoneyTwist has reached out with an explanation for why we see a difference between the expected miss chance (blue line) given the 13% theory and the observed data in the larger sample as indicated by the orange, grey, and green lines in the second graph. This will also have an impact on the third graph and smaller duration fights. I will quote his explanation here: “The observed miss chance trends below the expected miss chance. This is likely due to an antagonistic relationship between miss chance and dodge in which dodge overrides miss in the same fashion as dodge overrides crit, or crit overrides glance.” Let's introduce some terminology and Lemoney's calculation:

expected innate miss chance = eMC
predicted innate miss chance = pMC
dodge chance = DC

eMC * (1.00 - DC) = pMC

The above formula is used to determine what our predicted miss chance ought to look like once the overriding relationship between a defender’s dodge and attacker’s miss is accounted for. Let’s use an example of two players fighting and moving (13% miss chance), the attacker has 500 strength (-5% miss chance), and the defender has 20% dodge:

0.08 eMC * (1.00 – .20 DC) = 0.064 pMC = 6.4% predicted miss chance.

This would mean that 1.6% of the attacker’s miss chance is negated by the defender’s dodge.

I think Lemoney’s hypothesis is a definite factor and likely explains the differences seen between the expected miss chance and the trends in my data. You can begin to see this by looking at the chart below which uses the above calculation in conjunction with the eMC and DC in the data I collected to determine what we should expect our observations to show.

calculation.png


The similarity between the trends shown here and those in my results in the second graph in this guide are pretty close. After doing some testing on the side, I believe Lemoney has hit the nail on the head. But what does this mean for those of you that want to know the value of strength? You'll be happy to know I have a line graph for that as well:

dc.png


The blue line above represents a player being attacked with 0% dodge chance, orange 25% dodge chance, and grey 30% dodge chance. This is with both players moving. Because a defenders dodge overrides an attacking players miss in the combat rolls, you are hitting more shots than you may think and strength is not providing -1% miss chance per 100 strength. Actually, if the defending player has 30% dodge, it is providing -0.7% to miss chance per 100 strength.

The aim of this guide was not to give a complete and definitive guide to miss chance. Instead, the purpose has been to overturn the current understanding of miss chance and provide players with a more detailed understanding of the relationships between strength values, miss chance percentages, and player movements. In doing so, players should be in a better position to judge how much strength they wish to incorporate into their builds and be more aware of character movements and the associated impact on damage output.


Additional Information

I plan to update this guide now and then with details about miss chance as I test them.

Something that players have asked me, and I asked myself whilst writing this guide was "How long after a player has been moving and stopped does it take for the server or combat system to recognise that I have stopped moving?"

I decided to test this with dodge. I had a player stationary with 500 strength whilst auto aim attacking a stationary defender. As both players are stationary and the attacking player has 500 strength, the auto-aim miss chance should be 0%. However, as previously stated, a successful dodge counts as movement. As such, when the defending player moves via a dodge, that increases the attacking player's chance to miss by 3% (and their own by 5%). How long after a dodge do misses appear in the combat log? Three seconds is the longest I see, most clocking in around two seconds.

I want to caution players that this is over 2 hours of looking at a combat log and is nowhere near as rigorously tested as what has been previously outlined in this guide. This is also with a ping of around 120-130, this could contribute towards a delay. Whilst on the subject of lag, this was tested on TC where I was the only character(s) in the area, the delay on miss chance could increase further when you start to include more players such as in battlefields, invasions, and mass pvp.

That said, given this context, three seconds is the maximum amount of time it takes for the system to recognise a player has stopped moving and to calculate the new miss chance for the attacker and defender. I suspect most players will see what I seen, which was misses most commonly happening 2 seconds after an opponent dodges an attack. Don't take this as the final word on the subject.

Secondly, I have heard it said that certain abilities such as snipe, sniper shot, and dread strike have a higher innate chance to miss than other specials. I have even heard that there is code in the game files to support this claim. Over a sample of 500 dread strikes and 500 sniper shots, with enough strength to eliminate miss chance I didn't see a single one miss.

Outside of what any files may say, I suspect that players correctly identified that their big specials were missing more frequently than 1% when stacking 400 str (as guided by the outdated understanding of miss chance). As such, they incorrectly assumed an innate miss chance on these abilities. It wouldn't be feasible for me to go through each ability to check for innate miss chance, but since sniper shot and dread strike have now been shown to be subject to the 13% miss chance view, I believe this should be the default position for all specials subject to miss.

I have also heard that some players believe by using /prone or /kneel that they can avoid miss chance. This is also untrue. Again, this will be a case of some players noticing reduced miss chance while prone or kneeling due to their character being stationary and avoiding the +5% miss chance when attacking. They will still suffer miss chance from using auto aim (up to 5%) and the defending player moving (up to 3%).
 
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