Hi,

I did a small program to calculate chance of finding the key (without taking in consideration DP overhead) after a certain number or group operation.
Each value are the result of 100.000 trials so we can expect a precision of 0.3%.

0.5*sqrt(N) P=4.606 %
1.0*sqrt(N) P=17.162 %
1.5*sqrt(N) P=34.138 %
2.0*sqrt(N) P=52.314 %
2.5*sqrt(N) P=68.049 %
3.0*sqrt(N) P=80.350 %
3.5*sqrt(N) P=88.846 %
4.0*sqrt(N) P=94.103 %
4.5*sqrt(N) P=97.164 %
5.0*sqrt(N) P=98.746 %
5.5*sqrt(N) P=99.424 %
6.0*sqrt(N) P=99.752 %

I will increase accuracy and number of point and add a nice plot to the README of the Kangaroo program.