Which system or strategy would have the highest chance of winning money if used only once?

[77RedPhase]

let's say i wanted to use a roulette system or strategy only once.

if i bet on a single straight number in european roulette, i would have the lowest chance of winning on the next spin (36/37%).

now what's the opposite of that? in other words, which system or strategy would give me the highest chance of winning money if i used that system or strategy only once? betting on all 37 numbers wouldn't count because even though i would never lose a bet, i would still lose money on each spin since straight numbers pay out 35:1 and i would be betting 37 units.

would betting on 34 numbers be the answer? that would earn me 1 unit if i won and give me a 34/37% chance of winning while still earning money. or is there some system or strategy with a progression that if played once would give me a higher than 34/37% chance of winning and earn me more than 1 unit if i won using it?

 

[chillseph1023]

If you are too much scared of bad luck, betting two dozens or columns together could be the best bet for you.

 

[77RedPhase]

but betting on two dozens or columns would have a lower chance of winning than betting on 34 straight numbers (24/37% vs 34/37%). or are you suggesting some kind of progression involving two dozens or columns that would increase the chance of winning above the 34/37% in my example? remember that i'm asking which system or strategy would have the highest chance of winning money if used only once.