Today, I happened to type some random text and noticed interesting. This is a random sample of what i typed:

gh
jgh
jg
hjg
hjg
hjg
hjg
hjg
hkg
hjg
hg
jg
hjg
hjg
hg
hjg
hg
hjg
h
gh
gh
ghj
ghj
ghj
g
hjg
khg
hg
hg
hg
hjg
hjg
hjg
hjg
h
ghj

Notice how 'h' repeats a lot. It so happens that my middle finger was on 'h'. Perhaps, frequency is somehow linked to the length of finger? See table below. I used the keys G, H, J, K. My index finger was on G, middle on H, ring finger on J and little finger on K.

Table 1. Frequency statictics
Character ordered by frequency Actual finger on character Finger ordered by length

H

Middle

Middle

J

Ring

Ring

G

Index

Index

K

Little

Little

You can try this on your own. Place your fingers on the keyboard (horizontally, any other orientation complicates the situation as relative length changes). Probability theory suggests that the chance of occurrence of G, H, J or K is 1/4. But I think that in this case, probability is somehow weighted, proportional to the length of the finger.

This should allow us to predict hand position on a keyboard based on a bunch of randomly pressed keystrokes.