A couple of questions about a sentence

[anonymoose]

想到某个孩子之所以决定在学业上再做一番努力而不是辍学，某个孩子当有人向他兜售毒品时，能从毒贩子身边走开，这其中也有你的一小部分功劳时，感觉好极了。

Firstly, how would this sentence be translated into english? I understand each phrase, but I'm not quite sure how to make sense of them together. Perhaps it's the 这其中也有你的一小部分功劳时 part that's confusing me.

Anyway, what role does the 是 at the end of the first part play? Could it be said as 想到某个孩子之所以决定在学业上再做一番努力而不辍学 instead?

Thanks!

[roddy]

Basically, the sentence means something like

When you think about the reason a kid decides to make an effort at school instead of quitting, or a kid who walks away from the guy trying to sell him drugs, and you know that a little part of your work helped them do that, it's a great feeling.

It reads like a transcription of something spoken rather than something that has been written and edited for clarity, which is why it's a little harder to understand.

[anonymoose]

Thanks, Roddy.

And the 是 question...anyone?

[HashiriKata]

And the 是 question...anyone?

是 here is a type of 是...的 thing. Yes, (as a privileged non-native speaker ) you can drop it.