The best layout depends very much on what you want to use it for ...
From the above we can see that no one layout will be perfect for every use.
However we can still try to compare layouts, and use the results as a guide to picking one which is best for our needs.
There are different ways of measuring keyboard effectiveness, and each person tackling the problem takes a slightly different approach, leading to different results. It depends very much on WHAT you measure, based on WHICH inputs.
At present we are looking at two different ways of evaluation keyboard layouts:
Finger-based metrics try to measure how much work your fingers do while typing, and how easy/pleasant/convenient these actions are.
For example, we could measure
These factors are also tied up in the physical layout of the keyboard, of which in recent times there have been a veritable explosion away from the standard ANSI/ISO layouts.
So we have analysed the results from some popular layout analyzers, of which only 1 set is now available, others will be added in due course. You can interrogate the database and do your own comparisons for different categories etc. on the pages below, or you can view the Current Best Keyboard Layouts.
Many years ago, when Maltron launched their keyboard and custom letter layout, one of the selling points they used was to point out how many more words you could type on their Home Row, compared to QWERTY.
While correct, this comparison was a little disengenuous, because the concept of a Home Row, and even touch typing, did not exist when QWERTY was designed. So it was kind of like pointing out that your car has rubber tyres while your neighbour's ox wagon does not.
Be that as it may, counting words is still one way of comparing different layouts. Maltron used the Home Row, but modern layouts and physical designs have pushed the limits of where fingers go, and sometimes there is no such thing as a Home Row.
The alternative to Home Row is to simply use the subset, which is Home Keys... i.e. just the keys that your fingers and thumbs rest on in the "start" position. So for QWERTY that would be asdf, space, jkl;.
So I wrote a program to count how many words each layout can type, using the home keys. See the Home Key Words results.
Another variant of this, proposed by Xay Voong, is the concept of Home Block. This is the home keys for index, middle, ring and thumb, as well as keys naturally above and below index, middle and ring. The results for that are here on the Home Block Words page.
A more restrictive version of the Home Block is the Easy Block, proposed by myself. This is a block consisting of the keys which are easiest to type, namely home keys for index, middle, ring and thumb, as well as key naturally below index, and keys naturally above middle and ring. See the results on the Easy Block Words page.
Lastly there are words which get typed all on one hand. The classic examples for QWERTY are "stewardesses" and "minimum". For this test, a lower score is better, because otherwise there is insufficient alternation, and the fingers typically have to do gymnastics to finish the word. The results for that are on the One Handed Words page.
There are some issues regarding using word-based metrics to compare keyboards, as opposed to finger-based metrics: