Introducing Opal

Opal is an optimised keyboard layout using a magic key and adaptive swaps. There is also a version of Opal which has the letter E on the thumb, called Opaline.

Philosophy

From my experience with Sturdy, and from aggregated typing data from fast typists I concluded the folowing:

• Double letters (SKB - same key bigrams) are the same speed as same finger bigrams (SFB), so they should be treated the same and be optimised for.
• Some scissors are as slow as SFB, especially half scissors such as pr on Sturdy.
• Roll direction does not seem to have a significant impact on speed, so you should not make sacrifices in order to have the roll direction be in any particular direction.
• Whilst some redirects are horrible, some feel fine and even feel good. Opal and Opaline especially aim to reduce any redirects not involving the index or thumb. No types of redirects were rewarded in the creation process since the amount of nice feeling redirects are relatively infrequent.
• High movement index fingers do not feel nice. Instead of the 6 index moderate usage keys on the left index on Sturdy, Opal has 5, and Opaline has 4.
• Trigram alternation patterns, can be slow and innacurate. I think generally less alternations are better, but alternations can be useful in breaking up long one handed sequences. Rolls are strongly preferred to alternations.
• Row staggered keyboards have certain advantages, namely superior index keys: QWERTY N and M are equidistant to the home row keys, and the middle finger on the left hand has nicer keys. The ideal keyboard layout should take advantage of this. I strongly recommend reading Stronglytyped's take on this.

The inspiration for designing Opal is largely based on my experience of Sturdy, which I've gotten up to 179wpm on a 60s test over the last two years of usage. Like Sturdy, Opal is high in rolls, but without the left index movement, and scissors which have come to bother me when typing fast.

One thing that separates Opal and Opaline from other layouts is that they place a great importance on not only scissors but also skip scissors, i.e. scissors separated by one key. Furthermore, the scissor definition is more unique than what other analysers use, and penalises half scissors like QWERTY uk (though less). I found that when typing fast, your hands will adapt to scissor motions by having your hand complete the bigram in a motion, rather than just relying on your fingers. This hand movement isn't very comfortable but more imporantly is very slow. This layout was designed with the help of an analyser I wrote called Mana2 which generated most of the layout.

Opal is primarily designed for every day usage, and secondarily optimised for the default Monkeytype word list; e200. Opal relatively undeperfoms on quotes due to the overrepresentation of punctuation, which means the right index will have more same finger usage. You could modify the layout to fix this, but it comes at certain costs that I don't know are worth it or not yet.

With these in mind, I set off to make a layout which had a generally good assortment of stats and minimal glaring issues. I also wanted to have the nstd homerow, because I liked the types of layouts I had seen previously with this home row. I also decided to use the Reddit corpus as much of our daily usage involves this casual dialogue. The punctuation choices are also far more realistic compared to what you may find in books or quotes.

Opaline

Opaline is the thumb alpha version of Opal. By moving the E to the thumb, we can move the I to the old E position, and put the H in the old I position. This frees up space on the right index, meaning we can put the M on the right index finger, reducing the movement on the left index. After these swaps, some magic rules are added to clean up any bad patterns introduced.

As a result from these rearrangements, Opaline scores better on same finger usage, scissors, and stretches. Also as a result of the H pinky Opaline scores particularly high on inward rolls on the vowel hand.

One drawback of having E on the thumb, is that the pattern e_e is overrepresented in e200, and some may not like the same finger usage on the thumb. In everyday typing, the thumb SFS is less than that of the space.

Opaline works best on an Alice keyboard, which features a split space. However, it is certainly possible to use a thumb alpha layout on a regular keyboard. You just need to wide mod the right side, then use your right command/alt key for the thumb key.

Statistics

All statistics are with the Reddit corpus.

Opal Statistics

Opaline Statistics

The stretches and scissors have unique definitions to Mana2 so they are not comparable to other analysers' results. So I will also give the percentiles of the stats in comparison to all the layouts in the AKL database.

Opal:

• Scissors: 3rd percentile
• Skip Scissors: 11th percentile
• Stretches: 19th percentile
• Skip Stretches: 43rd percentile

Opaline:

• Scissors: 1st percentile
• Skip Scissors: 2nd percentile
• Stretches: 8th percentile
• Skip Stretches: 26th percentile

You can see the distributions for the other stats on akl.gg for Opal and also Opaline.

Whilst Opaline does feature generally better statistics, one stark difference is that due to thumb E on Opaline, it features far less rolls not involving the thumbs. Since the main fingers are physically closer to eachother it is easier to coordinate and execute the non thumb rolls. Though with that said, Opaline still does feel distinctly rolly in my experience.

With some alt fingering around the index and middle fingers, the repeats are less than 0.1%, with the only substantial repeat being rr, and the SFB and SFS also being slightly lower.

Testimonials

Coming soon!

Usage Guide

As previously mentioned, Opal takes advantage of the row staggered keyboard by utilising Nokwts fingering:

With this fingermap, the middle finger on the left side controls the keys T, P, and the magic key. The benefit of this fingermap is that it allows the middle finger to control a region of the board, rather than an arbitrary column. You should also use your left thumb for the space key on this layout. This enables more rolls on your thumb, and less alternations and redirects.

Some other recommendations for the layout:

• I would strongly recommend having the ? on the base layer, and then the / on the shift layer. The question mark is a relatively common character, and is far more common than the / character. This works well on the QWERTY ' position, just right of the I key on Opal. You could also have the " key there, separated from the ' key, however, this has less usage in quotes, whereas the question mark is relatively frequent in both quotes and every day typing, and you would need to find a place to fit the rest of the keys without pushing too many keys off to the edges.
• control+backspace on the capslock key. As you get faster, it'll be more efficient to delete a whole word and retype it quickly, instead of partially backspacing and using weaker muscle memory to complete the word. Usually this would involve holding down the control key and then reaching for the backspace key, but the capslock key is far easier to reach. If you still want the ability to turn on caps lock, you can have control+capslock turn it on.
• Sticky shift. This means that you only need to tap the shift key once, and do not need to hold it in order to capitalise a key. This is far easier to coordinate at higher speeds, though you can still hold the shift if you wish.

Magic Rules

You can always find the up to date magic rules on akl.gg.

This layout uses a magic key as well as adaptive swaps in order to improve comfort. A magic key is a key whose output will change depending on whichever key preceded it. So for example to type the word say, you would use the magic key and type sa✳, avoiding the uncomfortable ay half scissor. Another example would be with typing the word need, you would type it as ne✳d, avoiding the slow ee repeat.

The magic rules for Opal are:

• 'r
• ay
• hr
• ik
• jo
• ke
• rl
• u'
• ye
• else repeat

Opal also will use adaptive swaps in addition to the magic key. For example one of the adaptive swaps Opal has is u e/o, which means that after the U key is pressed, the E and O keys will swap their positions. So to type guest, you would instead type guost, and to type quote, you would instead type quete. This lets the more common sequences be the comfortable rolls, and the uncommon sequences the SFBs.

The adaptive swaps for Opal are:

• ' l/f
• j n/u
• u e/o
• y ,/u

And for Opaline, the rules and swaps are:

• 'm
• ay
• hy
• ik
• rl
• u'
• y.
• zy
• else repeat
• ' l/f
• e y/u
• l k/n
• r k/h
• u i/o

Usually in the discussions around magic layouts, there is a concern over a 'cognitive overhead' when typing. The idea is that due to the amount and complexity of the magic rules, your typing will be slowed down by thought rather than muscle memory or physical ability. In my opinion and experience, this concern is unfounded and completely overblown. Much like alt fingerings, picking up the various magic rules is simple and becomes pure muscle memory by a certain point, meaning that you do not need to think about how to type a particular sequence. This initial learning process is also very easy in my and others' experience in learning Opal.

Alt Fingerings

It's a good idea to alt finger as much as you can. Some sequences that are definitely recommended are:

• tt
• ✳p
• p✳
• e,

Additionally, you will find words where you can alt away an SFS, for example in the word too. In some words like "keep", it will be better to not use the ke magic rule, so that you can instead get rid of the SKB by typing ke✳p.

Modifications

e200 Focused

The problem on e200 for Opal is the rk sfb in the word "work". This is altable, but it doesn't feel great, and maybe worth tanking. We can't add an rk magic rule since its being taken up by the rl magic rule. And we can't replace the rl rule with the rk because then you have the word "early" which isn't altable due to your fingers on the vowels right before.

However there is a solution to this. If we replace the ay magic rule with an ar magic rule, we can then replace rl with rk, and now "early" is typed as ea✳ly, and we can now alt the rl in words like "world" comfortably. The draw back of this is that you now get the ay scissor, which in my opinion isn't worth it. Though if you are willing to tank some comfort for speed I would highly recommend this.

Installation

See the layouts wiki guide on installing a custom layout.

I recommend using Kanata, with Nova's Kanata Guide.

Frequently Asked Questions

How should I learn the layout?

I would recommend learning the magic rules as you go, most of the time the magic rule will be obvious as the non magic route is uncomfortable. The adaptive swaps will be trivial to learn as you are forced to use them. Besides this I would recommend learning a layout as you would normally, consider checking out "Practise for the beginner" from my typing guide.