Win, Wins or Won? Which is correct?
- "Why condition1 and condition2 wins over condition3."
Example: "Why teamwork and ideas wins over smarts".
Your clause -- "Why condition1 and condition2 wins over condition3." -- is typical for a title of an essay or article.
1. Which Aspect?
The given clause uses an aspect that indicates it's always true: in the past, present, and future. For that we use the present tense. This is called the "gnomic aspect", which uses the simple present in English to describe a general truth.
2. Is the subject singular or plural?
Next you need to consider the issue of whether the subject is singular or plural. The answer to this is based on whether or not you consider "teamwork and ideas" to be a single concept or two separable things. Unfortunately, this is not so easy with this subject!
2a. Maybe it's a singular subject.
A good argument can be made that you're pitting one thing (the combination of "teamwork and ideas") vs. another thing ("smarts"), and only one of them can "win". Thus we use the singular form of the verb:
- One thing wins over another thing.
- Why one thing wins over another thing.
- Why teamwork and ideas wins over smarts.
One could also say that if you use the singular form of the verb, you are in fact forcing the subject to be thought of as singular. In other words, plurality of the subject could be considered an issue of desired semantics instead of "correct grammatical style". However, this type of logic doesn't often win over fans of "proper" style.
2b. Maybe it's a plural subject.
Personally, I don't think so. But if you do think so, use "win".
Also, it looks very much like two (or more) separate things, so even if you consider them a single concept, it may "look weird" to use the singular. Some people will be unhappy with a singular verb form and will argue for the plural, "win".
3. "You can't win" (So change it.)
Unlike your proposition about "teamwork and ideas", you just won't be able to make everyone happy about either choice. But you can change it so it's more clearly singular or plural. The following is a singular subject:
- Why the combination of teamwork and ideas wins over smarts.
A good article on this can be found here: http://www.quickanddirtytips.com/education/grammar/compound-subjects.