I created this script in November 2013 after playing a Thanksgivukkah game of dreidel with my cousins. Once I realized that the gameplay involves new decision making and that it was going to take forever, I became curious if the game could be expected to converge to one player winning or if it would just go round and round without a victor. I created this script and found that it does in fact converge, after about a hundred rounds around the table for eight starting pieces each. I explored the parameter space and made some graphs.
The bottom line is if you start with more than eight pieces (10-15 is standard) you're going to be passing that dreidel around the table over a hundred times. I guess it keeps the kids quiet for a long time.