Yes, I understand why the third sentence is correct. The word "winning" in the sentence forms a gerund phrase because it acts as a noun. In this case, "winning" is the subject of the sentence and represents the action of winning the race.
To determine if a word forms a gerund phrase, you can follow these steps:
1. Identify the word that ends in "-ing".
2. Determine if the word is acting as a noun in the sentence.
3. If the word is acting as a noun, it forms a gerund phrase.
In the case of the third sentence, "winning" is acting as a noun because it represents the action of winning. This means that it forms a gerund phrase.
For more information on gerunds and how to identify them, you can refer to the resources provided in the links.