What are the odds of this working this well so far

Have been playing a stop win stop loss strag. realize that long term only counting can give advantage in BJ. but sucess so far with this over 275 hours in casino and up 87 units........also over the years have kept up with this on a computer game and it has worked at same clip ( % ) that has about 800 hours so combined 1075 hours and up about 240 units according to records.....what gives?? again no it cant last but how can it work ? this long ....flat betting also no raises double as basic strag dictates thanks ....