function y=driveend(ystart)

% y=end of drive (before FG attempt or punt)
% ystart=start of drive

for i=1:100
   if i<20
      q(i)=.9825;
   elseif i<40
      q(i)=.9825;
   elseif i<60
      q(i)=.9825;
   elseif i<80
      q(i)=.98;
   elseif i<95
      q(i)=.957;
   else
      q(i)=.95;
   end
end

y=2000;

u=rand;
c=1;
for i=ystart:99
   c=c*q(i);
   if c<u
      y=i;
      break
   end
end