Google can't evaluate something it has no records of. Same way a judge can't sentence a criminal without a history of his record (not sure if that's the best analogy lol).
But seriously dude. If you built 1000 links and only 50 got indexed, you are either:
a) Not using an indexer.
b) Not using a good indexer.
If I build 1000 links I can *usually* get about 400 indexed in the first week (with indexification). By week 2 those numbers usually pass 50-60%.
At that point I do a lazy, stupid thing where I resend all the same links for a second round of indexing.
The point is though, learn how to index your links. You can also and obviously add another teir in GSA. It will rob resources but if you do that on top of indexing programs you can get high index rates.