Question: If I have a site with numerous subcategories would it be better to have one domain with each subcategory linking off it, or a domain for each subcategory?

For example, if it's a sports news site, it might be something like:

```
sportsnews.com
sportsnews.com/football-news
sportsnews.com/cricket-news
sportsnews.com/tennis-news

```

etc.

The idea would be that there's an overall common layout to the sites, but the content and theming is different. 

The alternative approach would be something along the lines of:

```
sportsnews.com
footballnews.com
cricketnews.com
tennisnews.com

```

From an SEO point of view, is it best to have the one site with the rest linking off it so all the links to it are driving up the page rank collectively, or would it be best to have separate domains so that the domain, meta, title and description of each individual site all match up to the expected search keyword of `(sport name) news`?

If the latter approach were chosen, would linking to the individual domains from the primary one then be detrimental to the overall network of sites?

**Edit: Please note that sports is just an example. You can assume that although the subcategories are related 95% of users will not be interested in any others than the one they searched for.**

Answer: 
One factor in SEO is speed. Using different domains can affect browser caching and cookies and therefore speed. I think it comes down to if you think your average user is interested in more than one sport, if he would visit only one site then have different domains and just link between them. If he is more likely to want news on several sports then use one domain, you can still have the others redirect so `footballnews.com` redirects to `sportsnews.com/football` or `football.sportnews.com`
Would it not be best to have something like

```
sportsnews.com
sportsnews.com/football
sportsnews.com/cricket
sportsnews.com/tennis

```