In this particular example if ever the bonus given is $200, then the WR will be going to $4,000. Grand Martingale opens doors to more losses dependent on players' luck, where he doubles the bet and adds another unit if it so happens of a loss of revenue. https://hocvienboardgame.net/tin-tuc/choi-lo-de-tai-rikvip-trai-nghiem-thu-vi/