Nick is correct pilot slots are on a national level. What I would suggest is to talk to cadets at the dets and see how many are getting their 1st pick from a historical standpoint. You will do a summer comparable to LDAC. This also will help or hurt you because you will be there with ROTC cadets from across the nation. If you do very well then it will help you, i.e. DG.
The size of the det can also help, because if you get good jobs within the det., then it will help you compared to other cadets...i.e. flight commander in a det corps of 200 looks better than a corp of 50. Mine you, as freshman you will most likely not get a job, it is your soph that the jobs start opening. Also your job for your jr yr will be known before the end of your soph spring yr.
Your gpa, and ECs will add into the equation. You can enter as an engineer, which is preferable, however, if your gpa is 2.5, the AF might give that UPT slot to the non-engineering student with a 3.4 gpa and a member of Honor guard or AAS. The reason why is because UPT is also alot about academics, and if you are only book smart of 2.5, where the other cadet has managed the 3.4, jobs within the det, and the social organizations within the military they look stronger.
Your AFOQT score will also be placed into the equation. The higher you score the more points will be awarded to you at the board.
Your vision will also play into the equation.
Finally, the positive note that the AF has been stating for yrs., is that the % of cadets asking for UPT have decreased compared to decades ago where everyone and anyone had UPT as their goal. Now many want to be in the computer world and not fliers (the thought of long deployments has young cadets opting the computer world over flying). In our DS's det, only about 30% are competing for UPT, that still is @ 20 cadets per class yr out of 200 within the det, but for the last 3 yrs only 1 person did not get UPT. (GPA was below 3.0) So it is definetely obtainable to get UPT from ROTC.
Good luck.