Synchronised may have won the Cheltenham Gold Cup, but no horse has completed the Grand National double since 1934.
He is thought to have a low jumping action which may not be best suited to Aintree, while his price has shortened too much to 6/1 almost based solely on the fact that Tony McCoy is on board.
Junior is 9/1 to win the Grand National and this is largely because of his victory in the Kim Muir at the Cheltenham Festival last year, which is a race that Ballabriggs won en route to Aintree.
However, his official rating has gone up from 134 to 153 in the intervening period and there are reasonable claims that he will not take to the Aintree fences.
Like Synchronised, jockey booking seems to have held a major sway on the chances of On His Own.
He was 20/1 before Ruby Walsh was confirmed as jockey and this has now shortened to 10/1, which means he has to be opposed at the prices, especially given that he only has experience of six chase starts.
The other horse at 10/1 is Cappa Bleu and he should have no stamina issues, while the fact that Paul Maloney jumped ship to ride from State Of Play is a positive towards his chances.
But the anticipated rain has not fallen as expected and that is a negative.
Of those towards the top of the Grand National odds, it is West End Rocker at 11/1 and Chicago Grey at 14/1 that appeal the most.
Alan King does not often run horses in the Grand National and he may have had a winner last year if West End Rocker was not unfortunately brought down when travelling comfortably.
Since then the horse has won over the National fences in the Becher Chase, while he is also a former winner over 3m5f on heavy ground, suggesting that he will stay the trip.
Chicago Grey has been laid out for the National for a long time and loves a stamina challenge after a previous win in the 4m National Hunt Chase at Cheltenham.
Meanwhile, he fits many of the trends of former Grand National winners, including being aged either nine or ten and weighing between 10st11lb and 11st.