Quote from Bernoulli:
The only example in trading I can think of that is not chance is arbitrage, and I don't mean statistical arbitrage. Ask the guys at LTCM if statistical arbitrage is not a gamble.
I doubt that traditional arbitrage is an opportunity that presents itself to many ETers.
As for the comment about driving being a gamble, by the definition it is but not many people would buy that, nor would I. But on the other hand, with Russian Roulette, you are likely to live (83%) but I could call it a gamble.
So accepting a 6/5 payout on black and red is a bad deal ? It is not an arbitrage , you can lose a few ( many ) games in the row .