Random selections and probability in sports betting

Please help me make sense of this. How does including elements of total randomness to sports betting effect the likelihood of winning while following a Martingale system? (I understand all systems are useless in the long run, just trying to grasp this.) For the sake of my question, I start with 5k, and a $10 bet, cashing out and starting over after every win. Each day had a list of 20 basketball games on the betting board at the Mirage. (Obviously I have nothing to do with the order of these games.) I would place 20 chips into a container, each chip numbered 1 through 20. The 1st chip selected twice would be the game that would be played. (Random selection.) Then a best of 7 heads versus tails for home versus away team. The selection for the day would have nothing to do with knowledge, opinions, analysis, etc. Ridiculous randomness versus more randomness. How do the odds of losing 10 in a row in this scenario differ from picking who I "think" is going to cover the spread?? I hope this makes sense. I look forward to your responses.

I dont know, but if you were to pick the first chip selected twice, i think about 50% of the time you would get a chip between 7 and 13 inclusive...

Perhaps somebody can make a simulation to prove me wrong.....