age of how
long it takes to complete a piece. There is also a running average of the
deviation from the mean download time.</p>
<p>This download time is used as the benchmark to determine when blocks have
timed out, and should be re-requested from another peer.</p>
<p>If any time-critical piece has taken more than the average piece download
time + a half average deviation form that, the piece is considered to have
timed out. This means we are allowed to double-request blocks. Subsequent
passes over this pie