Yesterday, Google's John Mueller answered a question around Google's Gary Illyes saying you don't need to disavow for algorithms. John basically confirmed what Gary said, that you only need to use it if you have a manual action but added some additional clarity.
(1) He said you can 100% use it if you have a manual action and are unable to get the links in question to be removed or nofollowed. The manual action team will look at the disavow file and take it into consideration. Just a note from 2013, Google does want to see effort in manually removing links, not just using the disavow.
(2) You can use the disavow file to preemptively making sure you don't get a manual action in the future. It might not work 100% but John said you can use that.
(3) If you do not trust Google's algorithms are smart enough to automatically not count the bad links, then you can use the disavow. But logically, that doesn't make sense to me. If Google thinks the links are good, why block them? I mean, Google will automatically block the bad links anyway, if they think those links are good, why block them? Whatever.
Here is what John said to Glenn's question:
Question:
Glenn asks if there's been any change with regards to the disavow file. And there's some confusion out there as to whether or not it should be used or not or when it should be used.
Answer:
So essentially nothing has changed there for for quite some time.The disavow file definitely makes sense if you have a manual action that's based on link issues and you can't clean those links up. So ideally you would go in and try to clean those links up to either remove them or have a nofollow in place. If you can’t do that, then the disavow file is a great way to do that and can help with the resolution of the manual action. So after you've taken care of all of those problematic links pointing to your site, you can submit a reconsideration request and the web spam team will take the disavow file into account and lift the manual action if that's appropriate.
With regards to sites that don't have a manual action for link issues. We do try to kind of take those links out of the equation automatically when we can recognize them. In general that's something we're pretty good at. We have quite a bit of practice doing that, so most of the time we can get that pretty well.
If you're unsure as to whether or not Google is actually taking those into account or kind of taking those out of the equation then the disavow file is a great way to kind of get peace of mind and to say well I'm sure these won't get taken into account by any of Google's algorithms. And that way you're like absolutely certain that you're not associated with those links to your site that you can't remove or kind of change.
So in particular if someone is pasting links on a spammy site or maybe a previous SEO went off and ran some script to place links and a bunch of forums and you can't clean that up for whatever reason and you don't have a manual action but you want to make sure it doesn't even get that far, then the disavow file is a great way to just like preemptively say well I know about these issues, I don't want to lose any sleep over them, I'm just going to disavow them and get them taken out of the equation.
This starts 2:50 into the video, here is the embed:
Forum discussion at Twitter.