The aligned fraction of the aligned reads, which is chain length divided by read length. We fit a function of the form $1-{\displaystyle \frac{a}{m^b}}$, where m is the read length (x-axis), and display the resulting R² values. Aligned fraction is an upper bound for recoverability, and our lower bound on recoverability (and also aligned fraction) is $1-O\left({\displaystyle \frac{1}{\sqrt{m}}}\right)$, which the data suggest may be too conservative.