This was said before, but it'd actually be easy to build this max bet system mathematically, and only a little more difficult UI-wise, but not significantly more difficult than the current UI. The biggest UI challenge would be the expression of the size of the house bankroll, as it would have to be tiered, which would be ugly.
If we move to this model, I would eventually like to see a two basket approach like Betterment, where you can invest a proportion of your investment at a lower level and a smaller proportion of your investment at a (much) higher level. More coding, but still not much more work. The site already has two "baskets;" a gambling wallet and an investment. This would be just breaking the investment number up one more time.
why does it have to be tiered? the proposal I laid out (and the one I thought we were discussing) works exactly the way the current site works with no change to UI (except a field for investors to input their maximum risk per bet) and is not tiered - you can choose whatever risk level you want and it just works.
To use a very simple example:
Investor A has 10 BTC, sets risk at 0.25%
Investor B has 10 BTC, sets risk at 1%
Investor C has 10 BTC, sets risk at 2%
House roll:
30 <= 0.25%
20 >0.25% and <= 1%
10 >1% <= 2%
House roll for all bets <0.25% is 30, making the max bet 0.075
For bets between 0.25% and 1%, the house roll is 30 for the first 0.075, and then 20 for the rest: so the max bet is 0.225.
For bets > 1%, the roll is 30 for the first 0.25%, 20 for the next 0.75%, and 10 for the final 1%: total of 0.325
So a better comes in and loses a 0.075 bet:
Investor A gets 0.025
Investor B gets 0.025
Investor C gets 0.025
On the other hand, a better comes in and loses a 0.325 bet:
Investor A gets 0.025
Investor B gets 0.1
Investor C gets 0.2
Edit - added 0.25% bet case.