@Treswimming it just personal rule, not all people do it tho.
i mean, how can you give a score by only based on 1 chapter? usually in 3 chapter, you can know deeper what is the plot, where the plot is going, a small amount of character developments, and many more. it's not like it must be 3 chapters, it's up to you. i just like number 3 so for me, I'll look for 3 chapters before judging.