A small Ruby script to test Peter Donnelly’s example on uncertainity. Conference below..
def avg_pat(pat, t, s=0)
t.times do
last = ''
last += (rand(2)==0 ? 'H' : 'T') while last[-pat.length..-1] != pat
s += last.length
end
s/t
end
['HTH','HTT'].each{|p| print "#{p} #{avg_pat(p,10000)} "}