If your really concerned about rapidly changing events just add a diminishing return. AKA multiply both the success and failure number by say .9999 after each test.
so 34/2760 = 34.9966/2760.724 on success or 33.9966/2760.724 on a failure.
As to diminishing factor you diminish both the numerator and the denominator for a bucket every time you test that bucket. If you want something next to perfect try http://en.wikipedia.org/wiki/Bayesian_statistics, but that eat's a lot of CPU and is harder to code for minimal gain.