Well, I think that it depends on the state, the school district, the school and the specific classroom. I would also venture to suggest that a fun fiction sample is not the most relevant sample to judge by. You should look at how he answers literary typed questions and science/social studies/health type questions
Having made all those qualifications and based purely on our local experience, I would say that your DS' fiction sample is good for middle of K and okay for middle of 1st. However, it may or may not bar entrance to a tracked/GT 2nd classroom for the next year. In my school, that decision is not made until the end of the year. The fact that your DS is stronger in other areas would probably pushed him over but the writing would probably place him in the lower half of our previous tracked/GT classroom, which is not true GT but only about top 15%. Do keep in mind that your DS may really take off in the second half of K so the writing itself should probably not deter an acceleration if you are already set on it.
