Let me teach you the allintitle trick
Let’s assume URLs without the keywords in the title tag are not competitors, we can know the real numbers.
Using allintitle:keywords you will return URLs with keywords in the title tag.
Below 5 000 results, consider the query low competition. Between 5 000 and 10 000 results, it’s medium. Above 10 000, it’s highly competitive.
You can also use intitle: but results are looser.
There is nothing scientific in my tip, but it’s been working for me since I started SEO in 2004.
Moreover, it’s as scientific as Keyword Difficulty scores by SEO Tools.