Which is better, full-alternating or semi-alternating?
There are many guides and discussions on alternating vs. single-tapping, with advice like "alternating makes high bpm jumps easier, but single-tapping makes accuracy easier on slower jumps", but here I just want to compare and discuss the pros and cons of full- and semi-alternating. Would like to hear other people's experiences and thoughts on it. : )

TL;DR: My preliminary conclusion (which may change upon hearing your arguments/experiences) is that an expert in full-alternating should be able to play fast complex tapping patterns with more ease than an expert in semi-alternating, but that it's much harder to learn to be an expert in full-alternating. For some people, the benefits of full-alternating may not be worth the extra time it takes to be good at it. I'm not confident in this conclusion at all, and results could vary for different people.

By the way, if you want to learn full-alternating, McOsu has an experimental mod that forces you to do full-alternating (McOsu can be played without VR). There's also this program that uses an AHK script to force full-alternating in regular osu! (you won't get banned even when using it ranked). Also, this and this are good maps for practicing alternating (playable on half-time).

Terminology
Single-tapping is when you use only one key (e.g. X) for everything except streams.

Full-alternating is when you alternate between X and Y for everything. So if you look at the key counter on the right side of your screen while playing, the K1 and K2 counter will always be the same or differ by 1. (If the counter isn't there, you can reactivate it in the osu! settings.)

Semi-alternating is when you alternate between X and Y except for some complex note patterns. For example, suppose there are three consecutive triples in the song. Full-alternators would tap them with XYX YXY XYX, whereas single-tappers and semi-alternators would tap them with XYX XYX XYX.

Arguments for semi-alternating
• Semi-alternating requires you to learn fewer base finger patterns, so it is easier to learn and may be less complex to play (or maybe not, see discussion below). Here "base finger patterns" are things like using XYX for triples and XY or YXfor doubles. Consider the example from earlier, where you have to play three consecutive triples. The full-alternator uses two different base finger patterns (XYX and YXY) whereas the semi-alternator only has to use a single base finger pattern three times (XYX). The semi-alternator can choose to start every stream, quadruple, triple and double with X, whereas the full-alternator has to learn and use twice the number of patterns--both the patterns that start with X and the patterns that start with Y.

• Almost no top players use full-alternating. (Rustbell and Azer semi-alternate.) And since the top players tend to know what's best (goes the argument), full-alternating is probably not best. The counter-argument is that this argument is a base rate fallacy, and the reason most top players are not full-alternators is simply because it is very hard to learn and few people try it out. So even if full-alternating gave a significant advantage, we would still expect few top players to be full-alternators. The other counter-argument is: Bubbleman and Vettel. They're full-alternators and they're GOOD.

• Full-alternating is really hard to learn. I personally started out with single-tapping, and then after half a year, I decided to learn full-alternating. I found it difficult, but I eventually learned to do it instinctively (not saying I was good at it, I'm just saying that it felt like my main playstyle at the time). But I eventually drifted (unconsciously) towards being a semi-alternator because it was slightly easier and my brain reinforced the behaviours that were slightly better at producing dopamine (i.e. hitting patterns successfully). So even if you feel like full-alternating is your main playstyle, it could take longer to consolidate it as your permanent playstyle.

Arguments for full-alternating
• It feels smoother. Semi-alternating feels more like stuttering through complex tapping patterns tbh. Full-alternating feels smoother than semi-alternating, and that may mean that I need to practice semi-alternating until it feels just as smooth, or it may mean that full-alternating will always feel smoother even for experts at both styles. And I'm assuming that how smooth the different playstyles feel affects performance on complex tapping patterns (i.e. that it is important for the skill known as finger control). This is actually my main intuitive argument in support of full-alternating, but it's not a very strong argument.

• Full-alternating fast complex tapping patterns requires less complex hand movements, and may therefore be easier to play fast once you know how (or maybe not, see discussion below). Consider the three consecutive triples again. A semi-alternator would play them XYX XYX XYX, but this requires more hand movement than XYX YXY XYX because the semi-alternator would have to lift their X-finger before every triple whereas the full-alternator is perfectly set up for doing an YXY right after doing a XYX.

• It's cool. Almost no top player full-alternates? That just makes players like Bubbleman and Vettel cooler. They are unique flowers amidst swathes of grey blooms.

Which style enables higher speed?
It seems to me like there are two ways your speed could be limited. Either you have physical limits (i.e. your tapping-hand can't tap faster, or your aim-hand can't move fast enough) or you have cognitive limits (i.e. you're too slow in figuring out which instructions to send to your hand, or you can't read the patterns on the screen fast enough).

I argued earlier that full-alternating strains your hand less, because it requires fewer movements through complex tapping patterns, so you should be able to play higher BPM with full-alternating without approaching your physical limit than with semi-alternating. But I also argued that semi-alternating requires you to send fewer types of tapping-instructions to your hand (e.g. XYX XYX XYX is only one type of instruction sent three times), so maybe it enables you to play higher bpm without approaching your cognitive limit? Maybe, but I think the truth is a bit more complicated than that.

I think that, yes, in the learning phase, full-alternators will be limited by their cognitive speed limit for longer. They will have more types of tapping-patterns that they need to practice, so it will take longer to become good at them. But I also think that once a full-alternator and a semi-alternator has reached expert level at their respective tapping-patterns, the full-alternator will have the advantage. Why? Because the full-alternator will need to use fewer hand-movements (as explained earlier) and that means that they need to send fewer muscle-activating instructions from the brain. So if the cognitive speed limit is determined by the size and number of the muscle-activating instructions, then full-alternating enables higher speeds.

(For the unnecessarily technical-minded: the Kolmogorov complexity of the instructions sent by a full-alternator may be higher for any given osu! beatmap, but the speed-limit of the brain doesn't depend on theoretical Kolmogorov complexity, it only depends on the number of synapses and the total axonal and dendritic length it needs its action potential to traverse, and the length of that pathway which is myelinated and... ಠ_ಠ)

So I conclude with a graph I just made up. (Key assumptions: Full-alternating takes longer to master, but is superior once mastered. The difference between the two playstyles is small once mastered. The benefits of each unit of practice decreases over time.)

First off, let me thank you for you post, it was definitely an interesting and informative read.
As for my personal experience after roughly 120 hours of playtime of trying out all the things - including the aforementioned singletapping vs. semi-alternating vs. full-alternating - I couldn't make out any noteable difference for me.

At times I felt singletapping worked better for accuracy, and while I felt the results were there to prove the theory I could always replicate similar results or identical results with - for the sake of the argument - the other two tapping styles. The same can be said about the proposed benefits of both other styles, I never saw the difference.

Though I believe my - admittedly - failure to distinguish between them comes from a lack of 1.) dedicated practice and 2.) playtime dedicated solely to one style to perfect it enough, so take what I wrote above with a grain of salt, as with everything referencing personal experience as proof of concept.

My goal was never to "be at the limits of my (physical)ability" in terms of speed or pattern recognition, my goal has always been to play what is challenging to me, be it either through higher BPM or harder to read patterns. As such I never really had the time to - actively - focus on what my hands were doing (dedicated focus is - in my opinion - required to learn a skill). The consequence of it for me at least was that I chose to let my fingers and brain to their magic by themselves, do what they think is the right way in any given situation to play a pattern, a stream, tripled, w/e.

At times I will singletap using either my Index- or Middle-finger, fully alternate, semi-alternate or just mix everything up - which I guess is the most appropriate way to describe my particular way of playing -


(This section might be going a bit off-topic, but I do still think I make a somewhat interesting point here )

My focus is playing osu! as a rhythm game, which - again I hate to always point this out, but I do think it is necessary to avoid possible conflict over this matter - is the proper way to play this game instead of rigorously enforcing a particular way of play for its perceived/theoretical advantages over other styles.
Now do not misunderstand me, I am not suggesting this was your intention or anything, it's simply how I think a large proportion of the playerbase plays:

Sacrificing what feels most natural or most comfortable for benefits which you do not recognize until you are at a much higher level of play. Learning to fully alternate or semi-alternate should come much, much later in the learning curve, focus first on learning the basics, get a good understanding of how to play this rhythm game.

Now I kinda lost my train of thought here so I guess I'll leave it at that for now, if I do however remember what I wanted to say, I shall either edit my post or just make a new one here.

Enough of my gibberish, THANK YOU! again for posting this, as mentioned before, it was an interesting read that can - hopefully - lead to an interesting discussion on the topic.. Have a nice day, everyone!

Stamina should be considered as well. Tapping using the fingers isn't the only way to tap; one can also tap using the wrist or even the forearm.
Wrist tapping or forearm tapping not only gives extra stamina that semi-alternating playstyles need, it's also even more difficult to integrate said tapping techniques into the full-alternating playstyle, specially wrist tapping which seems to eliminate the need for full-alternating (most top players wrist-tap on anything slower than 1/4 or 1/6 beats). Because they compensate for lack of stamina (in semi-alternating), it's almost not worth full-alternating; it's easy to see why the majority of top players semi-alternate.

Full-alternating fast complex tapping patterns requires less complex hand movements, and may therefore be easier to play fast once you know how (or maybe not, see discussion below). Consider the three consecutive triples again. A semi-alternator would play them XYX XYX XYX, but this requires more hand movement than XYX YXY XYX because the semi-alternator would have to lift their X-finger before every triple whereas the full-alternator is perfectly set up for doing an YXY right after doing a XYX.

I disagree with this being a straight up advantage.
If you're full-alternating from the first minute of abandoning mouse-only (like me), you're well setup to run straight down into bad habits because you can get away with a much less efficient movement on patterns like that.
If a semi-alternator or singletapper plays XYX XYX XYX he is effectively training his streams and his stamina because the finger the pattern is started with goes at the same speed as an actual stream XYXYXYXYXYX.
If a full-alternating player is doing that, he is not training his streams at all, he is training triples.

This difference results in a significantly better learning curve for single-tappers and semi-alternators regarding stream speed and stamina. This is what I see as a major reason as for why full-alternating players aren't that high in rank.

Velura wrote:

First off, let me thank you for you post, it was definitely an interesting and informative read.

So polite! Thanks for a long reply! ^^

Velura wrote:

Sacrificing what feels most natural or most comfortable for benefits which you do not recognize until you are at a much higher level of play. Learning to fully alternate or semi-alternate should come much, much later in the learning curve, focus first on learning the basics, get a good understanding of how to play this rhythm game.

Well, maybe. When I started out, I put a lot of effort into thinking about the optimal ways to play and the optimal habits to form (e.g. mouse sensitivity, eye movement, mouse grip, and other mouse-related stuff) in order to be as good as I could possibly be in a couple of years. (Admittedly, I kinda like overthinking things, and treating everything as a science just for fun... : P ) I thought it was important to think about this early on, so that I wouldn't have to waste time changing habits later on.

And changing habits only slightly is really hard. For example, if I start out becoming good at semi-alternating, changing to full-alternating is more difficult than learning full-alternating from the start. This is because when you're already good at semi-alternating, the temptation will always be there to do semi-alternating instead of full-alternating, for short-term gain. Also, if you're used to playing XYX XYX XYX, and you're trying to force yourself to do XYX YXY XYX, the latter will be harder to learn the more used you are to playing XYX XYX XYX.

deemoplayer47 wrote:

Stamina should be considered as well. Tapping using the fingers isn't the only way to tap; one can also tap using the wrist or even the forearm.
Wrist tapping or forearm tapping not only gives extra stamina that semi-alternating playstyles need, it's also even more difficult to integrate said tapping techniques into the full-alternating playstyle, specially wrist tapping which seems to eliminate the need for full-alternating (most top players wrist-tap on anything slower than 1/4 or 1/6 beats). Because they compensate for lack of stamina (in semi-alternating), it's almost not worth full-alternating; it's easy to see why the majority of top players semi-alternate.

Oi, good point. I never thought about that you could tap using your wrist/forearm muscles in order to alleviate stress on your finger muscles. Switching between wrist-tapping and finger-tapping mid-song should give you more stamina, and it is easier for single-tappers to control which muscles they use for their taps.

But what do you mean "wrist tapping seems to eliminate the need for full-alternating"? Both full-alternating and semi-alternating seems to require finger muscles (maybe wrist/forearm muscles as well, depending on how you do it) equally much, except maybe semi-alternating which puts extra stress on one finger. Not sure what you mean.

Endaris wrote:

If a semi-alternator or singletapper plays XYX XYX XYX he is effectively training his streams and his stamina because the finger the pattern is started with goes at the same speed as an actual stream XYXYXYXYXYX.
If a full-alternating player is doing that, he is not training his streams at all, he is training triples.

This difference results in a significantly better learning curve for single-tappers and semi-alternators regarding stream speed and stamina. This is what I see as a major reason as for why full-alternating players aren't that high in rank.

Oh, interesting observation. XYX XYX XYX is sort of like streaming, except you skip three Y's. My counterargument would be that since you're skipping those Y's, that whole 3-triple pattern is so different from streaming that they're not very good streaming practice. I would predict that XYX YXY XYX is an equally efficient way to practice streaming. Both ways are negligible practice for streaming when compared to actually streaming, so it shouldn't be factor in deciding whether to full-alternate or semi-alternate. I think.

But yeah, the semi-alternator gets to train each of the base finger patterns they use more than the full-alternator, since the full-alternator has more base finger patterns they need to practice.

Mio Winter wrote:

So polite! Thanks for a long reply! ^^

Haha no problem, I take every chance I get to ramble on and on and on..

Mio Winter wrote:

(Admittedly, I kinda like overthinking things, and treating everything as a science just for fun... : P )

I tend to do the same, or as a close friend of mine put it very eloquently: " you play games to the death". I have a tendency to really get into a particular game, trying to learn as much as I can to be "The Best"

Mio Winter wrote:

And changing habits only slightly is really hard.

That is absolutely true - from my own experience - and breaking your habits willfully is a tough decision to make and requires constant effort.

Mio Winter wrote:

[...]already good at [whatever], the temptation will always be there to do [what you have been doing] instead of [what might be beneficial], for short-term gain

I hope you don't mind me taking this to another level of abstraction ( also sry for editing your post a bit ). This kind of takes me back to my initial post - also I think I have remembered what I forgot at the end of it - Most players - I think it is most or at least the majority of people looking for advice on how to improve quickly - tend to overemphasize the importance of one particular aspect and focus only on one particular type of skill, subsequently losing perspective for what might really be important or equally important. In this case learning to adapt any given tapping style might take away the necessary attention required to learn "reading",aim, "rhythm sense" etc. at a stable and steady pace.
(This might not really be a problem in actual play, since people are very different in how fast they learn and what is required for them to be able to learn, so in all actuality it might not be bad)

( A similar point is brought up in Azer's discussion video and I think it is worth checking out. It's only 4:49min so not too long: [Are new players headed the wrong way?])

Also, this is just a side note, but I didn't know you had added me to your friendslist

Mio Winter wrote:

Endaris wrote:

If a semi-alternator or singletapper plays XYX XYX XYX he is effectively training his streams and his stamina because the finger the pattern is started with goes at the same speed as an actual stream XYXYXYXYXYX.
If a full-alternating player is doing that, he is not training his streams at all, he is training triples.

This difference results in a significantly better learning curve for single-tappers and semi-alternators regarding stream speed and stamina. This is what I see as a major reason as for why full-alternating players aren't that high in rank.

Oh, interesting observation. XYX XYX XYX is sort of like streaming, except you skip three Y's. My counterargument would be that since you're skipping those Y's, that whole 3-triple pattern is so different from streaming that they're not very good streaming practice. I would predict that XYX YXY XYX is an equally efficient way to practice streaming. Both ways are negligible practice for streaming when compared to actually streaming, so it shouldn't be factor in deciding whether to full-alternate or semi-alternate. I think.

But yeah, the semi-alternator gets to train each of the base finger patterns they use more than the full-alternator, since the full-alternator has more base finger patterns they need to practice.

Well no.
The point is that the full-alternator won't learn to properly reset his fingers because he always has enough time to laze.
The main difference between XYX XYX XYX and XYX YXY XYX is that on the former you absolutely need to properly reset your X finger for the next note. And properly resetting your finger is something that makes you good, fast and accurate in the long run.
The full-alternating player is highly susceptible to not doing this, getting him stuck.

As mentioned, I've been full-alternating from the start and my movements are inefficient and my speed on streams and stamina is horrible in comparison to other people of my rank (and far below) even though I'm (probably far, don't wanna boast) above average on pattern reading and accuracy compared to other players of my rank. As you would sort of expect from 650h of full alternating.

With the meta heavily favouring aim, semi alternating is just more advantageous as you brought up, it's less mentally demanding (although from my understanding you don't really "alternate" triples if they are high enough bpm, you're including 1/4 and 2/4 timing in the discussion which steps in the grey area of streams and alternating, and it leads to a complete different discussion, but I'll indulge in your very specific example)

Endaris brought it up already, XYX XYX XYX simulates streams, just with 3 less Ys, if you learn triples you'll intuitively know how to stream, and vice versa as they require the similar muscle movement, developping muscle memory for both patterns, easier overall learning curve. and whether you like it or not the current meta is very aim heavy so your muscle memory for tapping is not a priority and it just best to have a tapping style that's consistent and easily recreate when similar timing pattern comes up, so you can focus on aim.

a relatable example for me is the piano, you learn scale, 99% of the time your tutor will tell you the order of fingers to tap the corresponding notes, rinse and repeat and you'll develop muscle memory for that. If you are given 3 consecutive sets of scales you wouldn't play the 3 different sets in 3 different tapping order, cause in practical environment you would have to also handle need to handle dynamic, articulation and speed, your coordination can only go so far you wouldn't bother to change tapping order.

But you might say "but N0thingSpecial you're still not addressing the theoretical possibility of a person developing muscle memory for two different taping order XYX & YXY enough so that it becomes intuitive", yes I do agree in a perfect world that perfectly dividing your tapping between both fingers is good for stamina and probably rhythm sense as you're so versatile with your tapping order, but to what extent does it stop being useful and it becomes redundant? why not alternate between 4 fingers? in piano if you need to play a single note rapidly you actually alternate between 3 fingers, but why 3? In a perfect world I could death stream 600 BPM if learn to shift my wrist and arm to alternate 5 fingers to tap 2 buttons. This is kinda where this discussion falls apart as you soon realise it's just preference.

N0thingSpecial wrote:

But you might say "but N0thingSpecial you're still not addressing the theoretical possibility of a person developing muscle memory for two different taping order XYX & YXY enough so that it becomes intuitive", yes I do agree in a perfect world that perfectly dividing your tapping between both fingers is good for stamina and probably rhythm sense as you're so versatile with your tapping order, but to what extent does it stop being useful and it becomes redundant? why not alternate between 4 fingers? in piano if you need to play a single note rapidly you actually alternate between 3 fingers, but why 3? In a perfect world I could death stream 600 BPM if learn to shift my wrist and arm to alternate 5 fingers to tap 2 buttons. This is kinda where this discussion falls apart as you soon realise it's just preference.

I've wondered why top players use two fingers to stream (maybe Gayzmcgee uses tap with pen as well? I'm not sure). Binding the Z, X, C and V keys on your keyboard to letters XZXZXZ should enable you to stream with four fingers, giving an advantage in speed and stamina (maybe not acc, but you can switch between using two and four keys). Is this even legal?

Anyway, I am a bit reluctant to start doing it, simply because I don't see other people doing it. It seems like such an obvious advantage that if I did it, it wouldn't be competing against other players on their terms anymore. It'd be like entering the ring armed with a machine gun. Kinda like the problem freedomdiver has with getting really high scores with touchpad--he's afraid he's competing using unfair means (read his profile). Is it even legal?

Binding your mousekeys to your keyboard is definitely not legal.
It exists as feature request and it was denied.

Endaris wrote:

Binding your mousekeys to your keyboard is definitely not legal.

I did the genius thing and actually read the osu!rules and they're just gold, lol.

3. Birthday threads are allowed only in Off-Topic, and nowhere else. All birthday threads must be accompanied with no less than three (3) images of dancing anime girls or they will be ruthlessly thrown under a bus.

But to the point, you're thinking about the following rule?

2. Play fair. Using third-party utilities of any kind to get any sort of advantage is not okay. This includes things like macro programs, aim-assist programs, timescale modification, and so on. If a program is doing something to help you play the game that you should be doing yourself, it isn't okay!

Or did you get the impression that binding M1 and M2 to C and V is illegal from elsewhere? This also applies to mapping C and V to X and Z, so that both the X and the V keys produce "X"?

Edit: Yeah, found the feature request. But I also found this reddit post, from a guy who asked peppy about it.

See my edit.
And be wary of the keylock anyway, that obviously wouldn't exist if 4 key gameplay was desired.

why so deep when you can just use every method from time to time from map to map

Kondou-Shinichi wrote:

why so deep when you can just use every method from time to time from map to map

Hm, I agree that using different playstyles for different beatmaps is often a good idea. But if you spread your practice time on several playstyles, your main playstyle won't be as good compared to if you only practiced your main playstyle. If I practice alternating even on low-bpm maps where single-tapping could theoretically give me higher acc, it will also make me better at alternating when I play high-bpm maps where single-tapping doesn't work.

But regardless, is there any beatmap where experts at semi-alternating should consistently outperform experts at full-alternating? If not, then there's no reason to practice both playstyles.

For me, usually i would use semi-alt + singletapping
a perfect example would be my slowmotion ezdt play

in reality, both full and semi alt pretty much doesn’t do a different

semi-alternators are most likely better on high bpm deathstreams on average

Great post! Lately i've been training full-alternating due to I have learned playing and doing triples etc with my middle and index finger. I feel like when I alternate my stream speed is worse than when singletapping because I singletap with wrist so I think it saves stamina for streams. Also Bubbleman full-alternates and he's currently #19

mikkoxd wrote:

Great post! Lately i've been training full-alternating due to I have learned playing and doing triples etc with my middle and index finger. I feel like when I alternate my stream speed is worse than when singletapping because I singletap with wrist so I think it saves stamina for streams. Also Bubbleman full-alternates and he's currently #19

The amazing BUBBLEMAN does?! : O Where did you hear this?

And yeah, that's one reason for single-tapping that deemoplayer47 mentioned earlier. Seems important.

Mio Winter wrote:

The amazing BUBBLEMAN does?! : O Where did you hear this?

And yeah, that's one reason for single-tapping that deemoplayer47 mentioned earlier. Seems important.

Yes he does! Well you can tell he's full-alternating from watching his plays and looking at the key counter.

Yep fast singletap players mostly use wrist / arm to tap, not their fingers. If we look Angelsim for example, he semi-alternates fast maps and I think most players just semi-alternate because they have trained streams / bursts with their main finger and starting them with that finger while alternating feels the most natural.