Just a quick reminder that, due to the sheer volume of bets placed on the Grand National, it may take Betfair up to 2 hours to close the market and settle all bets.
This can have a knock-on effect on your TBE systems.
If you are running a live system that places a bet on the Grand National AND you are using a recovery staking plan AND your results source is set to Settled Market, then you will not be able to place another bet until all of the bets on the market have been settled and the market has been closed on Betfair. This means that you are unlikely to be able to place any further bets on that system until 7pm or later!