can mod rewrite do this?

I have a bunch of websites and for years I've been user underscores to replace spaces in URLs....ie www . mywebsite.com/news_article.html

I've recently heard some crazy rumors that using a dash instead is better for search engines....ie www . mywebsite.com/news-article.html

So here's the mod rewrite I've come up with to do this:

RewriteEngine on
RewriteCond %{REQUEST_URI} ^(.*)-(.*)$
RewriteRule ^(.*)-(.*)$  $1_$2 [N]

Code (markup):

Is that a good way to do it?

Thanks.

 

Don't listen to crazy rumours. No difference at all between _ and -