If you're willing to move down in stakes ; if you have a bad run or you're not playing your A game , then your risk of busting using this approach is very low .
http://en.wikipedia.org/wiki/Kelly_criterion
If you're using 15 buy-ins with a 59% win-rate , your risk of going broke without changing stakes is [0.41/0.59]^15 ~ 0.004255 which is less than 1 percent . Since we play with a rake , this number should be a bit higher than that but probably close to 1 % .