t NEED to play with the Kelly Criteria, but you will end up with a lot more money than if you didnt and in the unthinkable bad streaks you hits (and you WILLLLLL hit those) you will feel a lot better because your bets will slowly be smaller and smaller.
A simulation with the Kelly Criteria, shows that if you play a 5 number sector with a 13.5% edge and a 10.000 bankroll your bank will develop like this with and without the KC.
If you flat bet 40$ pr number, 200$ pr. spin, your bank will develop like this:
100 spins 15200 $
500 spins 12200
1000 spins 25600
1500 spins 39000
2000 spins 45400
2500 spins 58800
3000 spins 73600
If you use the Kelly Criteria, starting out with the same amount: 10.000$ bankroll and 40$ pr. number (200 pr spin) it looks like this
100 spins 14650$
500 spins 7400
1000 spins 15200
1500 spins 28750
2000 spins 30100
2500 spins 66500
3000 spins 147350
NOTE: In this case the KC was a slow starter, and the flat bet came off to a better/faster start, but in real life we cannot know that. The +--+--etc. streak was equal for both scenarios. Both streaks had the same amount of hits placed in the same places.
Bottom line is, that the KC player could pocket 147350 (minus the initial 10 K) and the flat better could pocket 73600 (minus the initial 10K). The KC player had higher bets at some time but also lower than the flat better, but the KC player never risked more than 5% of his bankroll in a spin. Never.
The worst case were at spin 300 where the KC players bank were 6500 and the flat betters 8500. There were some heavy drawdowns for the KC player between spin 2500 and 3000 but at this point the bets were aiming for the table limits and obviously the losses are also bigger at this point.