https://osu.ppy.sh/s/76396
https://osu.ppy.sh/s/93555
https://osu.ppy.sh/s/142086
https://osu.ppy.sh/s/225677
https://osu.ppy.sh/s/41686

Any hard to read maps... Go with Nogard, Skystar, Rin, Broccoly, HanzeR or Hollow Wings maps.

If you're interested, Full Tablet developed a method of evaluating rhythmic complexity a while ago that might be of use to you.

Narrill wrote:

If you're interested, Full Tablet developed a method of evaluating rhythmic complexity a while ago that might be of use to you.

t/257272
I didn't know this thread existed!
We should combine our powers!

oh, how strange nobody says "play more" it looks like people are growing up

-

Nice necropost.

iderekmc wrote:

oh, how strange nobody says "play more" it looks like people are growing up

because this isn't a "how do i improve" thread...

ZenithPhantasm wrote:

Nice necropost.

It's not like the thread reached dead end so

Kert wrote:

ZenithPhantasm wrote:

Nice necropost.

It's not like the thread reached dead end so

Considering no one replied for 5 months I would say its dead. Now peppy will take all of our pp for necroing this thread.

wide jump and short sliders and yeah, skystar and fanzhen

-

Different patterns hold different object densities and challenges, however in general 90°angles do tend to be the hardest because you are not moving in a flowing motion as most movements in the game generally follow. This in mind, the difficulty of moving at an angle doesn't contribute to the difficulty of actually reading the note a super large amount. Patterns that change, however, do hold a larger difficulty in reading, and so it would make sense that patterns that are all 90°and change direction and shape would be the hardest to read.

This isn't with any calculations just a question for what people would think so here goes
Would closer notes that greatly increase object density and fill the screen up more, or would notes far away from each other and require more eye movement to do be harder?

Edit: would slider bodies be considered in how difficult they are to move in, such as fast long sliders being harder to read, or would slower bigger sliders be worse?

derminYagami wrote:

Edit: would slider bodies be considered in how difficult they are to move in, such as fast long sliders being harder to read, or would slower bigger sliders be worse?

A single slider isn't very difficult to read because players can remember it in some retrys. Also only fast sliders or slow sliders are not difficult to read too imo (e.g. fast sliders in the last kiai).
Frequent sv changes and overlapping sliderbodies could be really difficult for reading I guess. e.g. sv changes

omg imoutosan i love you

imoutosan wrote:

derminYagami wrote:

Edit: would slider bodies be considered in how difficult they are to move in, such as fast long sliders being harder to read, or would slower bigger sliders be worse?

A single slider isn't very difficult to read because players can remember it in some retrys. Also only fast sliders or slow sliders are not difficult to read too imo (e.g. fast sliders in the last kiai).
Frequent sv changes and overlapping sliderbodies could be really difficult for reading I guess. e.g. sv changes

Fast sliders very easy to memorize... https://osu.ppy.sh/b/821549 >.> <.<

Also, memorizing is the opposite of reading.

chainpullz wrote:

Fast sliders very easy to memorize... https://osu.ppy.sh/b/821549 >.> <.<

Also, memorizing is the opposite of reading.

I remember I said "A single slider"...
Of course, multiple sliders can be arranged into some really hard patterns (of reading), just like some hw's maps you listed.
And memorizing is the opposite of reading in some respects. But memorizing would affect the scores that players got. Since the topic is about the reading skills in scores, things that could be easily memorized should be somehow eliminated (or recalculated?).

Stacked, temporally unevenly spaced circles on Hidden.

chainpullz wrote:

Also, memorizing is the opposite of reading.

memorizing something is a good way to learn to read it and similiar things you might encounter later

when you know how it goes, brains have a better chance of making something out of the jumble on your screen

For me : AR 11, BPM >250, massive jump, and pattern

Im dyslexic so every map difficult waht !!1!1!!1!??

Hmmm...
1. Amount of elements on screen. The lower AR and/or CS and/or higher BPM the harder it is. (EZDT? This is madness!)
2. Suddenly changing patterns/speeds. Those are really hard to catch, the higher AR and/or bigger spacing the harder it is.
3.

Why you do this

vietnam13231 wrote:

Hmmm...
1. Amount of elements on screen. The lower AR and/or CS and/or higher BPM the harder it is. (EZDT? This is madness!)
2. Suddenly changing patterns/speeds. Those are really hard to catch, the higher AR and/or bigger spacing the harder it is.
3.

Dude, you need to stop necroing threads. Not only once but twice wtf

This thread isn't over though
Just saying

Does this mean I can make a post with examples that comes to the same conclusion that's probably already been posted in here before but I can't be arsed to read through this thread.

Because I'm bored enough to do that.

will osu!!skills ever be able to count all your scores? a lot of peoples ez score arent in their top pp, but would be worth huge in reading, the same thing for precision if somone sets a score on cs7 hr, but it isnt worth enough pp it wont be on their top precision, i find that this would be a huge issue for reading considering how low pp for ez is. i know api restrictions but i was just wondering

derminYagami wrote:

cs7 hr, but it isnt worth enough pp

Good joke.

Maps like https://osu.ppy.sh/s/74313 and this https://osu.ppy.sh/s/186340 are good examples of hard to read maps they have alot of tricky and oddly placed notes with lots of oddly placed anti jumps which are really hard to read imo Low AR and high bpm = hard to read and anything that involves anti jumps notes under sliders and odd mapping like skystar,hanzer ect is what i would consider hard to read. Also this for some reason even though I could read it fine https://osu.ppy.sh/s/33068

derminYagami wrote:

will osu!!skills ever be able to count all your scores? a lot of peoples ez score arent in their top pp, but would be worth huge in reading, the same thing for precision if somone sets a score on cs7 hr, but it isnt worth enough pp it wont be on their top precision, i find that this would be a huge issue for reading considering how low pp for ez is. i know api restrictions but i was just wondering

I made a request for a feature in osu!api, so hope peppy adds it. If implemented, it would allow us to get ALL plays from the time of implementation, but all past plays are still lost to the void, sorry

Khelly wrote:

Does this mean I can make a post with examples that comes to the same conclusion that's probably already been posted in here before but I can't be arsed to read through this thread.

Because I'm bored enough to do that.

As long you were not the one that came up with the conclusion, sure. Multiple confirmation is a good way to solidify a theory.

Well, I just FC'd a map, and I think this is the hardest map to read I FC'd so far (Even harder because +HD).
https://osu.ppy.sh/b/824633
Satomi Sato - Le jour [Lost Future] +HD (99.77%)

There are lots of circles behind other circles, circles half behind other circles, there is a slider that I always clicked before I should have clicked, there are 2 sliders that I always clicked after I should have clicked... Lots of hard patterns for reading, and it gets harder because of HD, as I said before.

I'm not exactly a pro player, but I hope this helps with your tests o/

I'm thinking to calculate how cluttered everything is by taking account total hitobject area, total overlapped area, and amount of path intersects or close to being an intersect. I'm just not sure yet how to put it all together yet.

abraker wrote:

I'm thinking to calculate how cluttered everything is by taking account total hitobject area, total overlapped area, and amount of path intersects or close to being an intersect. I'm just not sure yet how to put it all together yet.

Should toss in slider velocity changes and spacing (distance snap?) changes as well. Probably as a nonlinear function. Also something to account for the added rhythmic difficulty of patterns that start and/or end on blue ticks.

chainpullz wrote:

Also something to account for the added rhythmic difficulty of patterns that start and/or end on blue ticks.

I have actually been debating with myself whether to have timing changes as part of reading or not. I'm thinking to include them in tenacity, changing focus of that skill from how long you can do fast stream to how well you manage to keep the early/late "balance" and for how long. So essentially bpm changes, irregular 1/6 and 1/4 combinations, and fast long streams in a marathon map would produce the highest tenacity value if changed to such.

Another thing to consider is that there are basically 2 very different types of reading - density reading and speed reading. Density reading is pretty self explanatory. Lots of things on screen, have to pick out the order in which to click them.

Speed reading is a bit more nuanced but it includes the other extreme. Where you see so little of the overall picture at a time that you have to guess what is coming next if you want to keep up. Essentially when you take a map that's already technically difficult on ar9 and toss HR into the mix you don't really have the time to simply react to every stack, SV change, etc. Instead you develop a very general sense of what to expect based on how the music sounds (not song specific). Basically before a double even pops up on the screen you have this intuition for, this next part might be doubles. Having a general sense for what will come next is what allows you to recognize patterns at high approach rates.

Of course if the song is just your average ugu map it's pretty easy to know whats going to come next. It will almost always just be a mix of singles/sliders, a triple, or a stream. It doesn't take much reading to be able to do these sorts of maps at higher ar and higher ar also reduces the density reading requirement so overall people get the impression that higher ar is strictly easier to read or something (until they hit the speed where their eyes cant even keep up with simple patterns).

chainpullz wrote:

Another thing to consider is that there are basically 2 very different types of reading - density reading and speed reading.

Yes. I'm currently working on the Reaction Skill which takes account spareness chaos and then will be working on the Reading Skill which takes account clutter chaos.

This is probably going to be useless with explanations but at least it will provide examples.

https://osu.ppy.sh/b/5528 +DT

The first thing that would make a map like this hard to read is at 00:22:553 (3) - . A lot of these older maps have patterns like this where the notes go back directly ontop of themselves and it's sometimes difficulty to tell where the 4th note is placed. The actual hard part of reading this map comes at times like 01:31:810 (5) - where there's what looks like a clusterfuck of notes. It's actually just a 7 note stream that moves itself around then immediately ends with a singletap right next to it. If it were just a stack of notes it'd be easy, but I remember always missing this part because I thought it was like some triples or something.

02:00:238 (1) - is also hard to read. Even though the map is slow enough to do this, I originally played it as a double + single and would alt the stacked two and single the last one because the notes aren't all stacked on each other. They're not a double + a single, they're a triple. Very visually misleading.

02:27:003 (5) - This has the same problem as before with the 7 note stream but the timing isn't perfect so you just have to know this is double + quad rather than streaming through the entire thing since they're visually very near.

https://osu.ppy.sh/b/3990

This isn't a very hard to read map, but I'm not sure where to put this type of thing. It's likely an oversight. Now, everyone that I've shown this map to ALWAYS misses at one part and their acc is usually in the 80's. I have a 97% fc on this, but the one part that is hell to get right is 00:27:173 (4) - because that 4 is stacked AT THE EXACT SAME POINT AS THE END OF THE SLIDERTICK. There's no way in hell you can tell this visually. You just have to look in the editor to get it right.

I guess it's a little hard to read in places like 00:36:456 (4) - because you have to be keenly aware of the timing differences between the doubles since visually there is no difference on the screen. Repeat for 00:38:955 (1) -

For places like 00:55:558 (4) - it's a lot easier.

https://osu.ppy.sh/b/3556

01:06:806 (1) - Streams like this are a lot harder to get right and I have no clue exactly as to why because it seems you can aim down the middle of them to get it right. Perhaps it's because your aim needs to be half slower than it should be as a single line of notes?

01:14:449 (5) - The timing here is really janky and mapped to some random shit in the foreground of the song. The aim is also really spaced if you're playing this DT. As with 01:21:152 (3) -

The inconsistant timing and weird spacing combined make it difficult for me to do.

https://osu.ppy.sh/b/26276 +DT

00:06:725 (4) - Streams of doubles are harder because they make your aim have to correlate with each double you press as opposed to one note.
00:19:600 (3) - Like the last map with its timing and spacedness.
00:25:350 (1) - If I wanted to include ability to technically aim these streams as harder to read, I would include such things like this.


https://osu.ppy.sh/b/4635 +DT

It's harder because it makes you cycle between singletapping and alternating with weird transitions like at 00:22:248 (6) -
00:56:857 (3) - This slider is almost hidden? Seems very hard to discern
01:11:858 (4) - Sliders with no note spacing inbetween are harder to get right. You have to basically stream this and the previous section and end your tapping on the slider exactly.
What this map has going for it is that most of the individual notes are neatly spaced from each other.

https://osu.ppy.sh/b/193

This map mostly just has an AR issue in relation to its reading.
00:07:146 (2) - Without knowing what's going on you're originally going to be confused as to what's happening in the centre.
00:24:490 (1) - Stacked notes with this kind of weird spacing for them Double single Double are god awful
00:26:271 (2) - Timing change for these stacks is what the hell but I guess it matches the music
00:45:209 (1) - to 00:55:896 (3) - is hard to time right. You have to LOOK at the approach circles very carefully because the sliders won't match your rhythm.
01:23:271 (1) - Timing difference here always broke me until I forcibly learned it
01:39:584 (2) - This aim is hard to get right to sync with your tapping because it's so curvy, but I don't know if that counts as reading.
01:46:709 (1) - as before, this part usually breaks me if I'm not careful because of the space change.
01:50:271 (2) - Another section of triangles to easily miss on from tapping too early. Not sure why.

http://osu.ppy.sh/b/24315 +DT
00:47:967 (3) - Notes overlapping like this are hard to get right
Repeat for times like 00:59:798 (4) -
Overall not too bad of a map

https://osu.ppy.sh/b/19012

I fucking LOVE this map nomod. It's great for singletap reading. First of all, it's ar6 220 bpm if you're going to be singletapping it. Hitting every note like in 00:41:147 (4) - basically requires me to semi-snap to every single note individually rather than go through it like a stream. Thus patterns like 00:49:049 (2) - are hard to get right.

Once you've figured out your aim though, the only hard to read patterns become things like 00:51:459 (3) - with the stacking, 01:13:022 (4) - with stacking, 01:19:584 (5) - with overlap, 02:22:263 (1) - with having to aim in more than one direction between each note rather than in one, and 03:41:013 (1) - with making sure you follow the repeat slider to the end. I would always end it too early and sliderbreak. Probably because it's stacked undersomething else and hard to tell when it ends.

https://osu.ppy.sh/b/20305

Is another AMAZING singletap map. The reading in it boils down like mope where you have to semi snap to each note individually and aim for each of them or else you will miss. Consider this 00:48:563 (7) - where the notes kind of curve or around 00:50:479 (7) - as well. You have to follow the general flow of the "stream" or else you'll misaim for some reason. Same for around 01:54:525 (14) - where they're appearing side by side.

https://osu.ppy.sh/b/5413 +DT

This is hard to read in a very technical sense. The patterns aren't stacked weirdly on each other and there's hardly any shenangigans. It's just that you have to at 00:14:507 (1) - DOUBLE DOUBLE DOUBLE DOUBLE TRIPLE DOUBLE DOUBLE DOUBLE DOUBLE TRIPLE for many times in a row while having a quad at 00:21:149 (1) -
00:25:436 (4) - shakes things up a bit with some singles before forcing you to double again.

Entire sets of inconsistent amounts to alternate are confusing especially when done in a row like this

https://osu.ppy.sh/b/27690 +DT

I don't know what to say about this map. I can't even play it. It's like the grandfather of having inconsistant amounts to tap as well as notes stacked ontop of and around each other.

https://osu.ppy.sh/b/27368+DT

This map proves Wubwoofwolf is basically a scary ass motherfucker that's even better than you previously imagined. The series of doubles at the beginning is hard enough to get right, but you're juggling alternating every slider correctly ontop of very spaced "streams" of notes. It might only be 150 bpm streams, but aiming things like that is hard as hell on its own.

https://osu.ppy.sh/b/25953

The singletaps in this map are placed weirdly ontop of each other and I can't tell what goes where on sections like 00:27:298 (3) - and I refuse to actually memorise it because I want to be able to sightread it. Notice the 5 repeats ontop of the end of the original triple and not going back towards the beginning.

https://osu.ppy.sh/b/28286 +DT

Same as 777

https://osu.ppy.sh/b/19467

This is pretty much a harder version of mope with most of the same qualities. Patterns that are simply hard to read if you have the ability to aim the rest of the map are 00:54:880 (1) - for its repeated use of doubles, 01:02:630 (1) - for repeating exactly upon itself in an already awkward pattern, 01:47:130 (1) - for inconsistent stacking, 02:02:880 (1) - for also repeating on itself, 02:29:130 (1) - being like crocodile symphony's hard part, and 03:03:880 (2) - for doing much the same as some of the others but in a new exciting christmas tree pattern.

https://osu.ppy.sh/b/26707 +DT

My mate aireu spent time trying to fc this and I still have trouble passing it. At the 00:52:363 (1) - part just trying to hit every note becomes a challenge as I sometimes forget what the hell is even going on. I usually fail by 00:58:099 (3) -
01:02:290 (2) - Is also some timing jankyness.

I'm tired right now so I'll do more later since I'm only 1/3 through my old map collection.

don't mind me just a post in the hopes that khelly will continue his post once he's not tired anymore.
would be interested in the other 2/3rd .

PART 2:

http://osu.ppy.sh/b/24457+DT

This map I wouldn't place in the hard to read category as something that's difficult to comprehend. I place it as hard to read because it's so damn difficult to technically execute. Patterns that stick out more in the reading category are around 01:22:010 (4) - as triples that require you to aim in more than one direction.

What's technically hard about this map are triples like 00:05:914 (8) - that are in the shape of a triangle, 00:09:014 (6) - slider patterns from this into a single followed by having to kind of flow to the other triples and singles in a snake like curve, 00:14:114 (4) - for being a square shaped stream, 00:33:414 (6) - for nearly the same, 00:56:010 (1) - for being a sequential series of doubles, 01:08:810 (1) - for having hard aim as you constantly change directions, and 01:12:010 (1) - for being difficult to execute properly from constant triple to single action.

To be honest, I think figuring out multiple directional changes from the centre of each circle in quick succession is a good thing to look for. I don't know if you count the technical aspect of being able to play a map as reading but I sure as hell do.

https://osu.ppy.sh/b/23282

I'm just going to say I suck and that the first stream isn't hard to read but the sliderstream afterword is very awkward. 00:05:665 (1) - These triples all in a row like a stream are even worse than when it happens with doubles.

00:12:453 (4) - Having a 5 after the series of triples then a double afterwards is whiplash like.
00:17:545 (1) - This entire sequence of 1/4's is easy to misaim imo.
00:23:535 (2) - The entire patterns here are just the same thing but worse.

The rest of the map si the same with awkward 1/4 aim.

http://osu.ppy.sh/b/18170

THIS MAP SHOULD BE GIVEN A MEDAL. It's seriously one of the most fun hard to read maps I've played. I don't know if ar6 is the most fitting ar, but it's lower than the ar7 or 8 it possibly should have been given.

00:18:551 (1) - For starters, all aim like the patterns in this section are easy to miss because they don't seem to follow any good angles and it feels like your cursor is just floating around. That's the majority of what makes this map hard.

Especially when you have such large gaps like 00:23:646 (1) - that require constant cursor and tap speed that, in my case, are not synced at all.

01:03:765 (1) - THESE PATTERNS ARE THE EPITOME OF THAT. They're incredibly hard to get right. I think Abraker would call it control.

01:31:785 (1) - These patterns too are hard to aim for the same reason with 01:35:765 (1) - being one of the most difficult in the map imo.

03:16:222 (1) - This pattern begins what's actually hard to read and not just hard to get the aim right with the tapping. The hardest part comes from the colour combo switch where the pattern basically stacks ontop of itself but otherwise repeats.

03:19:486 (1) - I don't know if spinners like this count as reading but fuck are they hard to get. 03:22:590 (1) - ESPECIALLY WHEN YOU HAVE A SLIDER IN IT TOO? It's okay because osu lets you have two keys pressed so you can hold one and use the other for the slider. That's how to do it in wizards of winter anyways.

https://osu.ppy.sh/b/40248

00:56:523 (1) - I found on these sets of 5 I had to mentally hit one extra note than I otherwise would. I don't know if that's a me issue or if the 5 is somehow hard to read.

01:17:145 (6) - THIS TRANSITION FROM 1/4'S TO 1/2'S IS HELL AND I MISS IT 3 TIMES OUT OF 5.

01:43:941 (1) - I think this is the slider that caused me to 0 miss the map )) fuck I hate this

01:45:816 (2) - stacking ontop of itself and repeating is hard to get right.

01:49:014 (1) - SAME THING HERE BUT NOW WITH AIM LIKE MONKEY HITS HIS HEAD ON THE TREE HOW DO I DO THIS

http://osu.ppy.sh/b/27993

I can't pass this map. I don't have much to say about it because I don't have much experience playing it. This is a really good map to test your reading calculations on imo.

00:11:457 (3) - constant spacing like these patterns are hard to get right at lower ar and hell just in general.

00:16:169 (1) - holy mother of god why is this repeating on itself where do I start where do I am

00:23:573 (2) - I haven't played the rest of the map but having triples start on a slider like this seems to make it easy to sliderbreak. Especially with a note at the end of the slider and a triple afterwards

https://osu.ppy.sh/b/18577

The map that started it all with how I came to love old maps.

01:22:165 - Aim like this where you have to alt and switch directions is hell.

01:26:716 (4) - ^

01:34:390 (3) - ^ I think this counts too but it's probably just because it's more precise being cs7

01:35:950 (3) - The placement of this 3 in relation to the 2 and slider 5 is huh?

01:37:530 (4) - Having to go back from the 3 to triple the same aim again is hard.

01:40:572 (2) - Broken up alt patterns like this are hell.

01:45:989 (6) - Again with this stupid direction switching

02:02:472 (4) - The direction the triple went does NOT make hitting this 4 easy.

https://osu.ppy.sh/b/57382

Ar7 wasn't really a good choice for this map; it should be ar8 but that just makes it all the more challenging!

I don't really have much to say about it except that the jump spacing and this type of pattern makes it so your aim has to be very very constant with your tapping and it's hard to get right. Not really a hard to read map in the sense of clusterfuck patterns.

https://osu.ppy.sh/b/25580

This is the big black of 2009. It's amazing. It's the first sub ar 9 map I ever liked. It's actually quite nearly the same as raver's fantasy for most of the map.
00:32:811 (1) - This slidervelocity with these types of patterns are hard to get right if you've never come across them much before.
00:35:478 (3) - the angle is so unnatural 00:38:145 (1) - THE ANGLE IS SO UNNATURAL

01:12:312 (1) - Ravers fantasy aim vs 2.0

01:51:811 (7) - THE ANGLE

To be honest, it's actually a very crisp and clean map when I look at it. The aim is just incredibly hard to get right because, again, it feels like you're floating on nothing with nothing to grab on to. If that doesn't make sense, play any modern tv size and then a map such as this.

Ok I have 36 more maps to do and I will do more tomorrow. I was 1/3 through my list when I finished the last post but that's because I skipped all the uninteresting maps and all the interesting ones are at the bottom since I sort by difficulty.

Khelly, finish that list.

Alright so I've finally started working on the reading skill. Looking through all the maps laid out, I see more maps that deal with tap based reading than aim based reading. While tap based reading is pretty hard if you consider irregular tap intervals, sudden changes, etc, I think aim based reading deserves some attention as well. Currently I am working on the aim part of reading, then will focus on the tapping part of reading, and finally will bring those together.

So far the main factors that I think go into aim based reading are:

1. Overlaps - There are two types of overlap cases I can think of - a case where you fail to notice the note and a case where where the overlap obstructs the path. The first case mainly comes into play when either the player is required or happens to read too fast and fails to notice the note in time. This can happen when a circle is under a slider or the is almost or full overlap in some pattern. The second case can be analogous to a wack-a-mole game. A simple example would be randomly placed notes at two set locations, creating two stacks. You would essentially need to read approach circles to know which note to hit next. Also an interesting thing is that this require at least 4-5 notes to take effect.
   
   
2. Clustering - Koigokoro on EZ is a perfect example of such. To read clusters you either need to be able to keep track of where the appearing notes, approach circle differences, or follow points. I am not sure if there is really a peak limit to how many notes can be in a visible cluster before it's nearly impossible to do. What I do know is that note tracking (see below) becomes a factor when increasing the rate at which the notes appear. This one is hard to figure, so I would like more help figuring out how difficult this can really get.
   
   
3. Far note jumps - While it may have to do with how big your screen is and how away you are from it, this still is an interesting case. Far note jumps on their own are not hard to read, but they can get hard to read if you are not quick enough to notice the note in time. Your eyes are not focused on the note, so you can't really start pre-reading. It also takes around a bit less than 20ms the shift focus on the said note, so if this note is under another note or clustered among others, you will need to be a fast reader or efficient with your focus.
   
   
4. Tracking - Scarlet Rose is interesting because lowering AR does little to help with the map's pace. I initially thought this map is about reacting, then thought it is about having control. I wouldn't say there is too much clutter to blame on. You can generally make out what to hit next, but the fast paced sliders appearing at 1/2 measure at 320 bpm still makes it a really hard read. It is easy to loose track the direction the slider takes, the sliders are just long enough to require you to move, and combined with high SV, it forces you to keep your eyes on them. Make them appear in fast succession and it makes it hard to follow.
   
   
5. Fluidity Breaks - Those is more important when there is a sudden SV change or drastic change in note spacing or pattern rotation. The fluidity needs to be going on for a few seconds for a sudden change to be unexpected the first time.