1. Research the horses: Look at the form of each horse, which includes its recent performances, its track record, its trainer and jockey, and the conditions of the race.
2. Assess the competition: Consider the quality of the other horses in the race and how they match up against each other.
3. Look at the odds: Look at the odds that are currently being offered by bookmakers or exchanges, and compare them to your own assessment of the horse’s chances of winning.
4. Calculate the probability: Convert the odds into a probability by dividing 1 by the decimal odds. For example, if the odds are 3.00, the probability of the horse winning is 1/3.00, which is 33.33%.
5. Adjust the probability: Adjust the probability to account for any factors that you think the market may have overlooked, such as recent form, track conditions, or jockey form.
6. Determine the fair odds: Once you have adjusted the probability, convert it back into odds by dividing 1 by the adjusted probability. This will give you the fair odds that you would be willing to bet on the horse.
7. Compare with the market: Compare your fair odds with the odds being offered by the market. If the market odds are higher than your fair odds, there may be value in placing a bet.

Remember that pricing up odds for a horse race requires a lot of research and analysis, and there is always an element of risk involved in betting. Be sure to only gamble what you can afford to lose and to bet responsibly.