When I had my biggest win at Newbury, it was on a horse called Shangani. I followed my own guide when picking the horse, which obviously proved successful:

The horses previous race history: The horse had taken part in similar races (distance and fences) before, and was slowly improving with each race.

The grade/class: The grade was the same as the previous three races he had done well in.

The ground: The ground was heavy, and this horse had performed well on soft/heavy ground in the past.

The trainer: The trainer was Venetia Williams, who is a soft/heavy ground specialist and is really on form at the moment. One of her other horses had already won earlier in the day.

The jockey: The jockey (Tom Scudamore, who is very experienced) had been asked specially to ride this particular horse on this particular day in this particular race.

The weights: The horse was similar in the weights to how he had been at previous meetings where he had been steadily improving.

The track: This horse was a Newbury track specialist, meaning that Newbury is his favourite course and he tends to do well there.

The odds: He was second favourite all day, until he was seen in the parade ring, and another of Venetia Williams horses had already won, at which point he became favourite.

Other factors: The horse was a good age, looked calm/fit/well in the parade ring, was experienced over these types of jumps, hadn't had too much time off after his previous race and wasn't sporting any new headgear.