That’s really weird. I have tested WordAI and Spin Rewriter with Copyscape and the results were always 80%+ uniquness, even 90%+. I don’t know how u spun the content to achieve such low results, but this is definitely way too bad. As for the block spinning, I have to be honest, this is the first time I’m hearing of it and I will have to check it out when I have a bit of time, but generally, yes, in the best case scenario, you would manually touch your Tier 1 content to make it 100% human readable and as unique as possible. For lower tiers, you can do pretty much anything, but again, the better quality of content, the better results you will have. That’s in my opinion and experience.
Some writers browse for batches of cheap private ticket rights articles and spinning them before submitting them. These PLR articles might not be the best quality but anything can be much better upon by the spinner. These PLR content are utilised anticipated to the actuality that though the level of quality is average even, they possess helped catch the attention of in website traffic still.
Some article spinners out there require you to enter your text with properly formatted spintax to create the end result. To create formatted spintax, you'll usually need another tool. But Article Rewriter by Small SEO Tools doesn't require that. Instead, it does all the thinking for you, from taking in the context of every phrase to creating additional textual content that is as readable and meaningful as the text you originally entered.
SpinnerChief works in a similar way by polling its huge Cloud Thesaurus for the statistically best synonym. As the Cloud Thesaurus grows, so it gets better and better at synonym replacement. The cloud thesaurus supports more than 20 languages, including German, French, Spanish, Italian, Swedish and Portuguese (both Brazil and Portugal), Dutch, Indonesian, Greek, etc...
Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.