For a 50% chance you need odds of over 2.0 (regardless of bet size) to have positive EV. This is a bet of 0.4. With 2.0 odds the payout would be 0.8, and here

For a 50% chance you need odds of over 2.0 (regardless of bet size) to have positive EV. This is a bet of 0.4. With 2.0 odds the payout would be 0.8, and here it is 0.9? That looks like odds over 2.0 for 50/50 chance. So the individual bet is positive EV but the EV of an infinite sequence of such bets is still zero and that’s without the zero limit? There is just nothing in the article that begins to explain how that works. Maybe the video is better