If you set a numerical goal and it's too easy to achieve the kid might not reach his full potential. Set the expectation at top effort. Always think higher.
I expected my kids to get all A's. When they didn't we discussed the class. There were some classes a B was the best they could do. My daughter graduated in the top.10%. My son graduated in the top 5%. My daughter had SATs (math and English) in the 1400s. My son was in the 1200s. My son is brighter. My daughter is more mature and focused. She graduated PBK. She's currently #1 in her class in second year law. She was recently named editor of the law review for next year. My son falls out of trees, lands on his feet and says, "good score." He has a 3.6.
I told the kids if they got a 3.5 and 1200+ in high school there would be a lot of options. Sports opened the options even wider. The high school didn't overtly inflate grades for honors, AP and gifted classes. Th were inflated privately for class rank. Coaches asked for unweighted GPA, how many AP classes and SAT scores.