Captain’s Academy #41 is the definitive guide to how dispersion works in World of Warships. Enjoy!
holy shit i am early
that’s what she said
God I wish Alabama had a 2.0 Sigma.
God I wish my premium was better in everybody way than NC the tech tree ship…
I dont know what you guys are talking about. Both ships play exactly the same for me.
Nah, NC guns are a bit more accurate.Similar ships yes.
The differences are not that big. The NC and Alabama have the same horizontal dispersion but the NC has 2km more range so at the same range the NC’s accuracy is better. And the NC has a sigma of 2.0 while the Alabama has 1.9. If you are mostly fighting at ranges up to 15km you probably won’t see the difference but if you get near maximum range the NC hits a bit more reliable. And apart from the guns the ships differ in many aspects. NC has better AA (12 more Bofors), Alabama is shorter and therefore more manoeuvrable and she has the far better torpedo protection.
Overall they are very similar and I think a good example of how a premium ship can be different from a tech tree ship without one being better than the other.
Personally I think if you are keeping at max range for a game sniping at 23km, you are everything that is wrong with this game.
This is why I hate Roma and why I regret buying it. They should have not nerfed the ship to oblivion by 51% or something… They could have given soft nerf of 6%. Roma is a frustrating ship to play.
Yup, her guns are so inconsistent it drives me up a wall all the time, but I will love her regardless just because she’s one of my favourite historical ships
I know where you are coming from. But if you look at this from a World of Warships gameplay standpoint.. Roma isn’t competitive and it’s not a ¨worthy¨ premium ship. For me Roma is a Italian Captain trainer, nothing more. And WG nerfed this ship to the ground, and it’s sad to see the meta is so changed, and this ship has little to no impact in the match. It’s like Musashi now.. has a HUGE impact, but because it doesn’t have the 44 refit, Musashi will be less played when CVs are better.
CVs are already having a field day in the SEA server with the influx if Musashi and Yamato players because of the Haifuri missions.
The Super Unicum CV fishing divisions are out in full force. At around 9pm to 12am, every other game is a CV game at high tiers.
Roma is experiencing the Dunkirk problem, these 2 ship are in dire need of a sigma buff to curb the rage while playing.
Dunkirk has it worse even, high velocity with really low air drag X_x
Bayern is crying too…
Bayern has low muzzle velocity due to only carrying 380mm 45cal – short barrel guns, I find her pretty accurate…I was thinking more along the lines of Izumo, Gneisenau and Dunkek that utilise 50-52 caliber guns, so long barrel railguns with excessive muzzle velocities, and relatively low shell weight…
In short: Spam shots in cruisers
Also: Warspite can probably hit you on the bow, and her guns WILL penetrate.
Great vid I love the science behind the game.. I have been trying your blind torp runs. I only have Duca with long torps but I have been able to get lucky-skill torp hits. If I ever get Fletcher or gearing it would be interesting. I did complete the campaign for the ijn dd but have only played it once.
Nice video on explaining dispersion. But then why German BBs are tend to be more disperse(shotgun-alike) even it tends to have lighter, faster shells?(at least from tech-tree, as I feel the Konig SEEMS perform more consistently than Bayern)
iChaseGaming Thanks for such a instant response, cheers 😛
+iChaseGaming doesn’t König have like a 2.0 sigma while Bayern has a 1.8 sigma ? And having played both of those ships yes könig has way more reliable guns at short and long range, while mid range is still ok for Bayern.
She (König) had 2.0 Sigma. But some patches ago, WG changed the value to 1.8 too. She was “too good” lol. In the times i grinded the Germans ( more than a year ago ), i remember that the König was really performing good. Last time, my clanmates wanted to “sealclub” in T5, so i took my König with already the 1.8 sigma. She felt worse, but not as bad, as you will have with Bayern or especialy later with Gneisenau ( 6 guns only ) or even later with FdG ( cross-eyed Freddy xD ). Bismarck / Tirpitz performs not as bat at T8 and GK with her 12 guns and also “only” 1.8 sigma but with me using dispersion module, is really fine 😉
That’s because they have ‘continental’ horizontal dispersion (most, such as LWM, would refer to this as German dispersion). This is the worst horizontal dispersion line in-game, shared by German, Italian, and French battleships. American, British, and Russian battleships have a better horizontal dispersion, Warspite and Hood have their own slightly better line, and the Japanese have significantly better horizontal dispersion than anyone else.
Because they have a lower sigma value so their shells are going to be natraully more wonky than other nations, also, since the horizontal dispersion is linear per nation, the german BB horizontal dispersion is worse than that of the US and IJN BB’s
Why does this series not have a playlist. Jeeze.
I’m sorry, but: It’s usually spelled without the -second- third E.
The third, you mean?
Erm, yes. My bad.
If you are going to correct someone over the spelling of a fictional word, you should try extra hard not to be wrong yourself.XD Anyways, it took long enough to learn real English without concerning myself with learning the mechanics of fictional words. Don’t you find arguing over the spelling of fictional words a bit like fighting over the color of a unicorn? I mean they are usually depicted as white, but so what if I draw a brown one?
…Err… yeah… sorry.
Step 1: You aim at the Citadel Step 2: You get a bunch of water hits, a bunch of shots over the ship and an Overpen on the casemate. Step 3: You get hit by 5 citadels from an Amagi/Nagato/New York/Nassau/Whatever 18km away. Step 4: You cry in the forums.
BB play in a nutshell ^
Well, sometimes you get really tight shots and get 3-5 citadels instead (and it happens most with 12-inch guns).
Rng and dispersion make me hate this already mediocre game.
How does a lighter slower shell end up being more accurate….
angle of descent. Heavier shells keep their speed much better and tend to impact at much sharper angles, whereas slower shells will start to drop sooner, giving them much steeper angle of descent. This makes the vertical area they fall in smaller.
A lighter shell for a given caliber slows down faster, so at longer ranges the relatively higher drag causes it to arrive at steeper angles. This has the effect of tightening up vertical dispersion. Variations in muzzle velocity(it’s starting speed) have a big impact too. A more consistent velocity shot to shot is better too. Variations in muzzle velocity change the point of impact, especially at the relatively shallow angles which occur at shorter ranges. In reality shell flight times for battleship engagements could easily be around 30 seconds and at the maximum ranges possible, over a minute. Plenty of time for tiny variables to add up to 2-300m dispersion.
If you cannot follow iChase’s perfect explanation, then pick a book and study a bit of elementary physics… parabolic shots and so on.
The better (lower) the air drag (shell’s shape), and the heavier the shell (for a given shell shape and volume) the less energy will be dissipated by friction with the air during flight. The other way around the lighter the shell, or the worse the air drag, the more energy would be dissipated. The lower the energy which the shell retains, the lower its horizontal speed when its vertical speed is zero (so when the shell reaches its maximum altitude) and hence the steeper the angle of descent when the shell finally impacts.
Yes, it will impact holding less kinetic energy (and hence raw penetration value for the same given penetration “efficiency” or Krupp value) but it will: a) At long range be more prone to impact on the deck at a closer angle to the deck’s perpendicular reducing the effective thickness of armor to penetrate rather than bouncing off the thick belt (because there is more cross section of the target intersecting the impact direction which corresponds to the deck than the belt). b) Have less “vertical dispersion” (I hate this term) once again because of the steeper angle of descent: in the limit, a 90 degree angle of descent, so completely vertical, would lead to vertical dispersion = horizontal dispersion (a circle), 0 degree angle, so completely parallel to the horizon, would lead to vertical dispersion = infinity (no intersection).
Why the ellipse is an ellipse and not a circle: Because the volume in space covered by the salvo is approximated to a circle according to its “horizontal” dispersion, then when you tilt this cylinder and cut it by intersecting with the ground (sea) the shape you get is an ellipse: basic geometry, the more tilted (like when you cut a pickle not perpendicular), the longer the “vertical” dispersion.
So, yes, lighter, slower shell will have am intersection ellipse closer to a circle than a huge ellipse. BUT, its remaining energy will be lower, and the shell travel time will be longer, so by the time the shells fall, the target might have already avoided the predicted impact point, if you want an in game example: AP on Cruiser Yorck, try to hit anything at long range, good luck (due to its huge loss of energy).
I have a very special question… i didnt tested this one in game so please i have gun that has range 10km and dispersion 200m, if i use range upgrade mod my range rise to 12km… does my dispersion change to… 240? or stays same? if it stays same… in theory i should have more acurrate guns 😀
If you increase the range of your guns you also increase their dispersion. You can check this in the port menu.
Giving the dispersion in meters at max distance is quite stupid by WG. It makes guns very hard to compare. They should just give it in degrees, so the range doesn’t matter in the number. To answer your question: the degrees dispersion does not change with the range mod. So accuracy stays the same at any given distance.
Actually the dispersion improves slightly when using the mod(not the captain skill). I always divide the dispersion(m) by the range(km) and the resulting number is meters of dispersion per kilometer. It appears WG doesn’t scale this up all the way because on every ship I use Fire Control Mod 2 on, this number drops. With the AFT captain skill the dispersion number stays the same. Das Bat
Ichase why is wg making more bb with turtleback and bad dispersion, instead of making vulnerable bb with good dispersion instead?
lol they already did. It’s called cruisers.
Uh, IJN BBs?
Listening to EU forum? in which cloud do you live? EU forum has been “ignored” so many times it stopped being funny a long time ago.
Vulnerable BB with good dispersion ? Giulio Cesare is your answer
Look no further than Okt. Rev., Giulio Cesare and Nelson for exact sort of vulnerable, but accurate battleship you described. All three are heavily overperforming at their tier unfortunately.
Dispersion ellipse? Thankfully we called it beaten zone in military. We used to have a politically wrong video explaining why at short ranges it was ‘short and fat’ and at long range ‘thin and long’ because it was filmed in a bar looking at two chicks stood at the bar ?. Say no more ?.
iChase, does the game represent the IJN method of ripple firing which was more accurate combined with their higher emphasis on gunnery training compared to their opponents? By that I mean if the player copies them by rippling rather than salvo?
Just out of couriosity … do you mean each single gun (barrel) or each single turret?
Well, it didn’t do the IJN too well, USN ships generally scored much better hits thanks to much better radar targeting.
Ripple fire means one turret at a time, whether or not it’s more accurate depends entirely on training/engineering/doctrine etc. Barrels on turrets are always fired all at once, anything else would “jerk” the turret sideways and throw off the aim of the other guns. One of the problems with triple and larger turrets is that the sheer blast from the guns hits the backside of the shells and causes them to wobble, the US got around this by putting a delay coil into the firing circuit so that the left-right-center guns would fire in sequence (but still within milliseconds). I can’t find any reference to other nations doing this, for instance on some british cruisers the middle gun in a triple turret is spaced backwards compared to the other two, they were trying to solve the same problem.
+JoeyDee At the battle of Savo Island, IJN warships were able to close the distance on USN warships due to faulty radar, and the wonderful powers of the Japanese “Mk. I Eyeball”.
The IJN didn’t just utilised “staggered firing” for “safety reasons”… Apparently it was discovered that firing a 3 turret salvo, resulted in the middle barrel – to have really morbid dispersion – as it was effected by the blast waves produced by the 2 outer barrels. So the Japanese made sure that the spacing between the guns on the turrets – for the Yamato class were pretty wide… Not to mention – they utilised staggered firing – by firing the first 2 outer barrels – mili seconds apart before firing the middle barrel – another mili second later – for the best dispersion characteristics – in tandem with their god tier optics (IJN were famous for their optics, thus explaining their amazing ability in night battles in early wars of ww2, that USN eventually outclassed with Radar FCS).
I don’t think this way of thinking about ‘vertical dispersion’ is correct. After all, why should the plane of ‘vertical’ dispersion be in the plane of the water? (I.e. the x-y plane), should it not be in the plane of the ship?(x-z plane) What needs to be done is from the dispersion ellipse from the water, do a calculation for the dispersion ellipse on the plane of the ship and plot that. The result should be that faster shells have shallower arcs which mean that the dispersion ellipse in the plane of the ship is less pronounced than the one shown in the video. I don’t believe that the vertical dispersion is the major contributing factor in the lack of accuracy in Roma and in KM BBs, rather I believe it is the sigma value and the maximum dispersion at range to be the issue.
Well explained there Angel33Demon666. I think it is particularly important to understand it is the x-z plane that really need the focus here. Though it is not well illustrated in the video it must be the combination of sigma and max range dispersion to be main issues.
As for the “troll dispersion” of German BBs (and Roma), it probably comes down to these factors: 1. They use German BB dispersion formula, which is less accurate than other BB lines 2. Long arming distance thanks to high velocity – even broadside Omaha will overpen Bismarck shells out to 12km, you can try in Training Room for yourself 3. Shallow fall angle, which leads to bigger vertical elipse and more misses 4. Relatively low 1.8 sigma, though even 2.0 sigma Scharnhorst isn’t renowned for its accuracy, since it still suffers heavily from the first 3 issues listed.
#3 is the one folks struggle with. At shallow angles of arrival, it takes less variation in muzzle velocity or a shells ballistic performance to make larger changes to dispersion. Roma had historically bad consistency in shot velocity, and some texts also comment about highly variable shell quality. I don’t know if that’s covered by her sigma value, but that would make sense to my understanding.
because he cannot show the vertical vertical dispersion, there’s not vertical water surface that records shell impact 🙂 that’s also my main gripe with the vid, but he does what he can with the tools available … his graphic and explanation is perfect if you do ground bombardment with the battleships however ….
And what do the dispersion upgrades change? (the 7% and 11% one) The sigma or the horizontal/vertical dispersion?
The horizontal dispersion, you can see it in port, idk if it changes vertical dispersion though. Sigma is a constant value though.
If I had to guess the module probably wouldn’t affect the vertical dispersion given it’s a function of a ballistic calculation (velocity, air drag and mass). It does however reduce the horizontal dispersion as seen in port stats. Please correct me if I am wrong.
I think you’re right mate
I do not agree that high falling angles and better vertical dispersion is an advantage in terms of sheer accuracy. What matters is vertical dispersion measured perpendicular to the trajectory of the shell rather than measured in terms of the horizontal plane. Take the view at 4:53, true that the two ellipses are different, but also bear in mind that the two types of shells will ‘see’ this ellipse from different angles when they impact the sea, so from the shell’s direction, the two dispersions would be similar if not identical or even reversed.
TLDR I do not think vertical dispersion *on the horizontal plane* (as quoted in game) is a objective measurement of accuracy, falling angle at the same range needed to be quoted as well
Similarly cf Angel33Demon666’s comment below
Yep, this is how I thought it was too. Good understanding.
It bothers me why iChase never takes this into account, but it’s also true that American AP shells are much more reliable at doing massive damage than the german shotguns.
In theory, shallower shell trajectory should not miss a vertical ship any more than steeper trajectory, but in practice it does result in more misses: https://i.imgur.com/JlEv1XT.png
If you’re interested in an exhaustive explanation, have a read through this very recent thread on r/wows: https://www.reddit.com/r/WorldOfWarships/comments/7r1qwe/the_case_for_low_muzzle_velocity_in_wows/
PangUnit yes and yes, I fully agree with you on this, we are talking about different definition of hit here. I was making a simplistic explanation, ignoring water, underwater pen and other factors, only considering whether a shell eventually reach the hull or not. Your case is a level above and many more factors will come in. Nonetheless, both goes beyond the explanation provided in the vid.
Yeah but this doesn’t explain why gneisenau has 6 highly inaccurate guns which cannot hit anything. Shells land miles away from the target….
Hehe, why did it absolutely not surprise me you did this video shortly after Roma’s release.
Poor Roma … she’s suffering a massive identity crisis where her guns are way too inaccurate at range, and her citadel way too fragile up close where her thick belt armor doesn’t mean squat. In fact, she’s turning into Alabamagate 2.0 as that’s exactly the problem that ship had during development.
Do you think they’ll ever either buff Roma’s accuracy so she’s better at range, or drop her citadel to the waterline so she’s better in a brawl? She’s a bit of a red headed step child right now :/
Either RNGesus is with me or the Roma’s guns are better than they look on paper. After 13 Roma battles I stilly have over 87K average damage and just yesterday I once again hit a Bismarck at nearly max range for 20K damage and a Yamato at 13km that was bow on for 10K and after I baitet him to show his side he got some nice citadels for over 40K damage.
My own damage numbers are also above average, although you beat me there. My concern with Roma is how RNG her shells are. I love the fact that they are so fast that targets have little chance to respond, but then when the shells arrive, it’s a total roll of the dice whether they’ll do anything at all, *especially* against cruisers. Being a stealthy BB, I want to be in situations where I line up a shot just right and can expect my shells to at least have some regular pens on target. Not wiff all around it. I’ve had games where I dev struck two cruisers back to back … and then I had another game where I was being chased by a Charles Martel and from some four full volleys, not a single shell penned or citadelled it and the CM just ended up burning me to the ground. I don’t expect every ship to have Yamato accuracy, but I do want to be rewarded for good aim at least somewhat reliably.
The short shell travel time to the target you mentions seems to compensate the lack of accuracy and iChase also mentions that if the Roma hits she often hits very hard.
You are right about it being more satisfying when your shells hit more reliable. But the vertical dispersion of the Roma is the downside of the high shell velocity and having a higher sigma or having more accurate guns in general would probably make her too strong (my average damage in the Roma is 20K higher than with the Bismarck or Alabama…). It seems the overall package of the Roma works and for me she is a pretty (and) fun ship that does not make especially the Bismarck and Tirpitz obsolete.
See, that’s the thing … I find her fairly underpowered right now. Her AA is garbage and her citadel is massive and very easy hit up close. I’d accept the whole dispersion vs shell flight time as a good balancing element if it weren’t for the fact that this ship has notable flaws elsewhere. Personally, I’d love to see her citadel dropped down to the waterline (or as others have noted, put her citadel much deeper in the ship as she’s supposed to have been designed) so as to allow you to take risks to get in closer if need be. But right now, she’s stuuuupidly easy to dev strike. I should know … I used Roma to dev strike another Roma 😉
Good explanation of horizontal/vertical dispersion and sigma, but:
How does “locking on” to ships ingame change this mechanic ? From what I’ve seen locking on will improve sigma drastically. This should be mentioned for the “Definitive Guide to Dispersion” 😉
Should players aim differently depending on dispersion ellipse? I’m not talking about lead here. IMO with North Carolina shells, one should not aim for the waterline when shooting at long range. If the dispersion ellipse is drawn on the water surface, then statistically, the majority of shells will fall short. Is this the case ? If yes, aiming higher, depending on the width of the ship should provide better results.
Please don’t get me wrong, iChase did a very good job explaining this stuff and I’m critisizing here because I see room for improvement. This whole mechanic explanation should have been WGs job in the first place, so thanks to iChase for doing their job again.
Chase, these are great videos mate. I really appreciate the time and effort you take to explain very technical ‘background’ aspects of the game in a clear and simple way….. all of which will hopefully make us better players who will gain greater enjoyment from our games. Keep up the great work.
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