flare, I will answer this questions again:
The Navy needs X number of ET's, EM's MM's. The detailers do their best to match the ones that want to be ET's with the available number of ET slots. THERE IS NO MAGIC FORMULA. At the beginning of the selection process, as long as you meet the applicable rating minimums, which every potential nuclear student does, then all are equal. Put down on your request sheet what you want and the Navy will put you where they want you. You can ask the question as many different ways as you want, but the answer is the same.
P.S. Don't ask the same question on multiple threads, it clutters up the boards. This thread will be merged.
Have A Day 
-Matt (soon to be retired MMC/SS and newest NEO at CPNPP)
I was recently briefed at boot camp by a master chief stating that there is an exact mathematical formula applied, followed by personal preferences, followed by needs of the navy. Needs of the navy was made to sound less important. Aptitude was the highest indicator. Then the ONE guy (every Friday) (not this master chief, someone in Tennessee) would look at what the computer generated via ASVAB scores and subscores, looked at personal preferences, and first put people in their best aptitude then moved them in order according to ASVAB score into their preferred rate. This is where needs of the navy came in. Each rate had to have some great scores, good scores, and ok scores. ONE guy figured it out each and every Friday. The computer "printout" creates rankings based on a combination of your AFQT, NAPT and ASVAB subscores. If you did not take the NAPT, no worries, there is no advantage to taking it or not taking it, all else equal. Prior service, private experience, college, AP courses, high school grades, personality,medical, waivers, financial, security clearance, etc. do not figure into this printout, nor does this ONE guy know about any of that. It's that simple (COMPLICATED).
So, there most definitely is a magical formula. While this is a recollection of a brief a few months ago and it may have been designed for recruits as opposed to staff I think it's accurate, at least its logical. It is certainly recent. If you do better at electronics, you might be an electronics technician or electrician's mate. Haha, needs of the navy. So your ASVAB scores outdid yourself (grammar intentional). ASVAB/AFQT/NAPT were "needs of the navy," too. In any event, needs of the navy can also determine the magnitude of people needed in a rate. There is a double track of MMs going through the pipeline now. So, that pile of recruits was bigger, and there were 2 MMs for every 1 (ET+EM). To me, it seems as if nearly everyone who wanted their rate got it. Don't get freaked out if you don't get your preferred rate though, there are advantages to each. If your an accidental MM, make your friends call you petty officer for three months in between when you graduate A-school and when they graduate. Your job is different but you still get to work and live with your friends. If your an EM on the outside but an ET on the inside, you still get to hang out at reactor controls. If your an "MM" who turns out to be an ET or EM, you get the "comfort" of reactor controls or the benefit of electrical equipment/motors/gearheads/whatever. Figure out how to put a 2 Farad capacitor in your labor of love car. That'll teach 'em.
