A basketball star must battle his vengeful mother’s attempt to sabotage his championship hopes when a posthumous letter from his long-lost dad reveals the young man was abducted and raised under a false identity.

The way I read this: The young man’s mother has given him a letter from his dead father revealing that she ran away with the young man (who I assume is her own son since you say nothing about his real mother) and raised him under a false name. And she gives him this letter at this moment to mentally upset him while he is playing a basketball tournament because she wants revenge for some wrong we don’t yet know about.

At its core you have a story about a basketball player who has to overcome some personal issues to help his TEAM win the championship. The problem your story faces is that the personal issues do not seem all that compelling. The usual reason women run away with their own babies is because the men in their life abused them. The idea that the woman is extremely selfish and ran away with the baby so she could have it all for herself is far fetched. All she has to do is tell her son his father beat her and he will believe her because it is far more likely than the alternative.

I think you are trying to juggle too much in one logline. Concentrate on the relationship between mother and son and relegate the father to a subplot not mentioned in the logline. Tell us why the two main characters are at war with each other and what is at stake for each.