People get carried away with the Grand National but sadly there is no value whatsoever nowadays. For example, Big Fella Thanks, which is already miles too short at 9-1, will start at a much shorter price - I'd guarantee that. At least half the field will start at 20-1 or shorter, which is ludicrous for many reasons.
I gave up betting years ago, and I'm still astounded at the amount of people who will throw their money away and blindly accept the odds offered to them instead of walking away. 9-1 should be the odds offered for a horse to simply complete the course safely, let alone to actually win the thing.
My only advice for those who must bet on it is this:
1. Do not bet on any horse carrying over 11st.
2. Unless your fancy is between 9 & 12 years old, don't bet on it.
3. If the going is either very soft or very firm, check that your fancy has previous form on that particular type of going.
4. Do not back a horse with an amateur rider on board, or a female jockey.
5. If you take a chance and gamble before the day(ie you'll lose your money if your horse doesn't run), you're virtually guaranteed to get better odds now than on the actual day of the race when most money is bet and the odds shrink.
6. Do not back a horse simply because of the jockey, ie the current champion jockey Tony McCoy, has never won the race.