Hit Modfiers

[jwsmith26]

I spent a couple of hours documenting some of the modifiers that affect Hit Rate. This list was derived from a single portion of one battle that took place between France and Italy in 1906. This is a very small sample from early in the game so I make no claims that it is comprehensive in any way but it does serve to illustrate just how complex the hit probability system is in the game. I am sure there are additional modifiers that I didn't encounter in my small sample (such as rain).

I used Ver. 1.32. I've compiled my findings in an Excel spreadsheet I've attached. I have also attached the notes that I took during the test. They have some situational information and observations that I made at the time that may be useful if you're interested.

I'm sure we would all like to have some idea of how the hit modifiers actually work within the hit formula. It would also be useful to know how the Basic Hit Chance is derived. I'm talking about a general description, not the actual formulas used.

Even without knowing the formulas, the values provided do allow some useful comparisons, assuming they are all handled the same in the hit formula. For instance, it puts crew training in perspective. The best crew training can be more than nullified by the target ship simply turning. Hitting a ship when it is end on to you can have almost as much impact. Anything between you and your target - smoke, rain, another ship, all add up very quickly. Good luck trying to hit something if you're also maneuvering, or under fire, or your guns are firing at the wrong size ship. Heck, even your Fire Control is a negative most of the time until you get directors. It all paints a very gloomy picture for gunnery and its quite amazing that any hits are scored at all.

Here are some things I noticed in this little examination.

One thing that is noticeably absent are any modifiers connected specifically to speed. Several of my ships were traveling at their maximum speed but there were no speed modifiers listed. Perhaps speed enters the equation in some other way?

There are a number of modifiers triggered by maneuvering of either the firing ship or its target and these can be quite severe. I noticed that even minor course changes of just a few degrees would result in a -10 modifier but the negatives really ramped up (all the way to -70 for one DD) if your ship was making very tight turns.

I'm not sure what Tech level represents. I noted that the highest tech rating was for a DD, certainly not the most advanced ship in the fleet. Even stranger, the Tech level for the Lyon BC changed over the course of 20 minutes.

I was surprised to see that 7" secondaries produced an interfence modifier against 12" guns. I didn't have any 6" secondaries to test to see if they also interfere.

There is a modifier for Ship Class but what is strange is that it varied between -20 and -60 for the destroyers I examined, none of which varied in size or ability substantially. I don't know what this variation simulates.

Please feel free to add to or modify the spreadsheet.

Attachments:

RtW Hit Modifiers.xlsx (9.43 KB)

Hit Modifiers Notes.txt (5.92 KB)

[Fredrik W]

The tech level modifier is based on your fire control research, but varies with gun type and range. The general effect is that heavy guns will become comparatively more accurate at longer ranges as technology develops.

[jwsmith26]

Thanks for the info, Fredrik.

[admiral]

Speed affects accuracy, but it's about the target, not the firing ship. Next time you see a heavily damaged ship or a TR, look at the accuracy report and it will say something like "slow target speed". I believe it's a +20 modifier.

Accuracy of this period is all about adjusting your elevation and training after watching your shell splashes. When ships move past a certain speed, they move past splashes as you observe them, complicating accuracy adjustments. However, since the target moving quick enough to degrade accuracy is the rule rather than exception, this degradation of accuracy isn't named. Instead, we get a bonus when ships move slowly because it's the exception to the rule.

This is also the reason why your own ship speed does not affect accuracy. Chances are, your ships are at such a long range that no matter how fast you're moving, you will never pass the enemy ship as fast as it could pass your shell splashes. 

[director]

The reason is also that your ship's speed and course are exactly known to your own fire control while the enemy's course and speed (and rate of change, which is more important) are guesstimates.

One reason for the superiority of American fire control was that it was almost entirely automated. Other fire control systems had humans making observations or receiving reports and entering numbers into the system. That slowed down the reaction time and introduced errors.