The player who knows the sequence for liberties as a function of eye size (1, 2, 3, 5, 8, 12, 17) has an advantage over a player who has to read the capturing race. The general formula is
L(n) = (n^2-3n)/2 + 3
for 2 <= eye size n <= 7. Subtract the enemy stones inside to determine the number of eye liberties remaining.
Instead of using that formula it might be easier for some players to remember: '3is3, 4is5, 5is8, 6is12'. The first number is the size of the eye in question the second number is the amount of liberties it is worth before(!) and enemy stone is placed inside. To memorize this read it out loud repeatedly.