The author also noted:
> yes this has to buy below 0.73 long term, the bot has a configurable ceiling set at 0.65 and checks for new markets buying closer to .5
What happens if you flood the market with a bunch of implausible bets like "sun won't rise tomorrow"? Sure, you might try to filter that out with some sort of "seasoning" period (ie. don't buy new markets), but then that means more time for arbitrageurs to correctly price the market, depriving you of any price advantage you might have had.
Of course, once you add a condition like that, the probabilities change....
That presumes that there are people selling into new markets at 0.5 without thinking about the actual odds.
For this question I'm working on https://polygains.com
What other question would you like to be backtested? This one is fairly easy