Interestingly, Google does not open search results in a new tab or window. But…I mean… what could Google know about links, they’re not in the business of… …oh, wait… 
…links are a core part of their business activities. They seem to be doing fine as a company, but, this points to that thing I alluded to earlier: when the content is high quality, we always find our way back.
Anyway, there’s really no debate on what is the better practice. It has been discussed to death by heads far more learned and level that any of ours… to the point that the W3 has made a recommendation. We are free to observe or ignore it. 