How to... commentate on a horse race

Before commentating on a day's racing it is crucial to spend the night before going through the card. I get printouts of each race and spend around three hours familiarising myself with each horse's colours, the jockeys, form, whether it likes to come from off the pace and, if it's a flat race, where it's drawn. I like to know 60 per cent of the horses off the top of my head by the time I go to bed, and I'll spend the following morning brushing up on them.

One of the most important times for a commentator is when the horses are going to post - during this time I notice any significant markings that they have, like a big white face, or if they are wearing blinkers or a nose-band.

During the race I look for horses that are travelling well, not just ones that are up with the pace. If a horse is in midfield and still on the bridle you know the jockey has plenty left up his sleeve and can expect him to challenge. Also, certain jockeys' styles are easy to spot - Frankie Dettori and Pat Eddery are both very distinctive.

To see things more clearly I use binoculars, which I inherited from Peter O'Sullivan. We also have TV monitors, but I usually leave them to my spotter John Hanmer, who assists me during commentary - he's like my safety net. He can talk to me through my ear piece and tell me if I'm calling the wrong horse home or if there's a horse coming through I haven't noticed.

The hardest race of the season to commentate on is the Royal Hunt Cup at Royal Ascot - 30 runners over a straight mile. Everything goes so quickly. Sometimes the field splits in two and they run on opposite rails. You need to be very alert, especially if some are running in similar colours.

The Grand National is the race I still tend to get what I call 'toey' or nervous before - not because it's a tough race to call, more because of the pressure that is on me to get it right. I am aware of how many people are watching and the fact that everyone has had a bet and wants to know where their horse is. I think the key to commentating on a horse race is clear thinking and to have a very good short-term memory. You also need to have the reactions of a slip fielder.