Chances of getting a H1B after MBA STEM in US

Hi everyone, I have been reading around here for quite some time and I still can't find a concrete answer about the probability of getting a H1B if you got an OTP and therefore have three attempts to enter the lottery. I keep seeing some wild things thrown here an there, some people say is 10%, some people 80%. Can someone provide an answer (with some calculations behind) and maybe some reliable sources. I mean it seems strange to me that people embark in such expensive programs without actually quantifying this.

Thanks.