All of the options provided are not how I do race selection.

Race selection is a key part of being profitable and 99% of people don't do it at all or don't do it right.

Race selection is only partly about maidens, form, weather, etc. These are things lots of people already factor into their betting. "I only bet on Good Tracks where all horses have had at least 3 starts" is a common race selection technique. But this is basic race selection.

Here is my interpretation of race selection and how I do it. I won't reveal how or even the factors I take into account as they are key to me beating the rest of you. But I can provide some theory.

Race selection is about knowing the race. Its about understanding if 1,2,3, or 10 horses could win. It is about knowing how many can be ruled out as losers. Its about predicting improvements or losses in form on all the horses. From this you should know the minimum and maximum performances you can expect from every horse in the race and how they relate to each other which then tells you the likelyhood of it being a profitable race. Its about odds as well. Regardless of your research if the odds are not showing a certain way then it could be an unprofitable race to bet on even if you think there are only 3 chances. It could also suggest betting on 7 out of 10 horses is a great idea. You don't know till you understand the race, the horses and the odds market in combination.