A gambler stakes $1.00 on a red number on a roulette wheel that contains 18 red numbers, 18 black numbers and a 0. If a red number turns up, he gets back twice his stake. if a black number turns up, he loses his stake. If the 0 turns up, he gets a second spin (for free) and either losses his stake if a black number or another number 0 turns up, or wins back his stake if a red number turns up.

If the gambler plays this game a large number of times, on average what would his net winnings (or losings) be on each game?