Any Martingale/chase system has a high risk factor. You need to string together long winning streaks and avoid that ONE loss that might break you. If that loss comes early, you can kiss your money goodbye. If it comes late in the season or after some profit has piled up, then you might have some profit leftover. It's all about when that loss occurs.
Looks like the Over came through. 70 units saved.
If you can't stomach the risk/loss, then stay away from it.