Comment Authors link opens in same tab by default. Previously I was using Better WordPress External Links. It shows icon in external link. Also opens all the external link in new tab. I had some problem with that. So I had to leave it. Also you can make links open in new tab in post. So leaving that plugin does not have much effect. But then I saw that Comment Authors Link opens in same window. Its a problem for me. I don’t want them to leave my site. It will be great to Open Comment Authors Link Open in New Tab. For this we have to make get_comment_author_link opens in new tab. this is a simple process. You just need to add a code snippet to functions.php of your theme file. I have applied this code to my site for now.
I also thought that Google will penalize for links opening in new tab. But i have found no document regarding this matter. Here is a discussion in Moz.com shows that it is not verified. You can add open links in new window for third party websites, not for your own domain. This is actually a part of link building strategy. Google says:
In general, webmasters can improve the rank of their sites by increasing the number of high-quality sites that link to their pages.
Ranking at Google Webmaster Central
There are 4 types of links. One of them is Outbound links that means you have a link on your site that links to another site. So you should have some outbound links that points to high PR site.
How to Open Comment Authors Link in New Tab:
Add the below code to your theme functions.php. Go to Dashboard > Appearance > Editor. Select your theme from right side bar. Select functions.php
If you have any problem, let me know.