Why is this?

Back a month+ ago I created a tumblr blog to rank for a couple keywords, I also created some webpages on another site to just try to get extra traffic If I can. I built no backlinks to these extra webpages I speak of, but I have been trying to build lots of backlinks to my tumblr site. So today I stumble upon one of the so called extra webpages when I'm checking for my keywords and I see it is on page 1, but my tumblr site is like on page 3. Just to be safe I check this webpage on page 1 for backlinks and none are picked up. So this begs the question why is this?

There seems to be no rhyme no reason to search engine results sometimes, is this a fair evaluation?

maybe it has a exact match in the domain? I've also experienced stuff like this.. search engines are machines, the only logic is the algo behind the search procedure.

Is the Tubmlr blog links to one or more of your ranked webpages?
This kind of a method is called: "parasite hosting" where one tries to use the power of authority websites to try and rank them or with the help of them other websites or the one itself. It was a very common seo ranking method back in the days where spammers and others too ranked authority webpages of famous platforms such as Academia webpages, Facebook, Twitter, and more with the help of external links.


But, in time, Google has shut down almost completely this method.


So...
Maybe Google found out that you're trying to spamouflage your Tumblr blog and thus wont rank it.


Another possible solution, with continue to "parasite hosting", is duplicate or nearly duplicate content across pages. Is the content on your Tumbl blog a duplication (or spun content) of one or more your website pages?

No my tumblr content is unique, and no the tumblr does not link to this high ranking webpage I speak of.

Google has shut down almost completely this method? i see many sites are still with this method,and rank well,how to explain?

That has to be your back-links strategy i guess there is something wrong with it..

These are competitive keywords and I have not gone hardcore in getting backlinks really for my tumblr blog yet, but some is a whole lot more than none lol. So I would hardly consider my backlinking a failure yet, page 3 is not bad, it's just not as good as page 1 with zero backlinks.