The selection process is a once a year for each rank Staff Sergeant (SSgt. E-6) to General. 60 days prior to the selection board a message is released and it has a series of Military Occupational Specialties, MOS(jobs) listed by the corresponding number of who has promotion slots and who does not.
Some MOS' have several other MOS' "feeding" into other MOS. Such as, 6423, 6432, and 6433 feed into 6434.
The MOS' are listed by the feeder MOS and ones that stay the same in numerical order. In that list there will be several columns referring to the criteria for promotion. It is broken up into 3 sections, the above zone ( Marines who were in zone the year prior that did not promote), the zone (Marines who were not looked at the year prior), and the below zone (Marines that have not been in any zone thus far).
In each zone there is a column for Date of Rank (DOR - when promoted to present rank) and the Armed Forces Base Date (AFBD - when entered in military service). Usually, the above zone lists the AFBD as N/A, but this is not always the case.
45 days prior to the convening board, another message will come out with "tweaks" or changes in matters of number of allocations to date time frames that are eligible.
The board selection process is performed by higher ranking Marines with at least one officer for enlisted boards. Each board member receives a "jacket", which consists of Service Record Books (SRB) , Fitness Reports (FitRep), and any other information that the Marine sent to the board or is listed in other administrative records, for each Marine eligible for promotion. Each board member gives a brief (about 2 minutes) for each Marine's Jacket that he or she may possess. The board then takes that information and votes on who should be promoted.
In the case of the SSgt. promotion board, the board convenes in mid-July and the results are posted usually a few days prior to the first week of October. The list will state the names, MOS, and a number, which states the order in which the promotion will take place. The order is listed by the most senior Marines first and then descends to the most junior Marine. (Senority is time in grade (rank) then time in service.)
~~A side note~~
I may missed something here but all this information is available at the Marine Corps website.
So back to the question at hand, Do I think I will be promoted?
I would like to think I am the best candidate for the next rank and will do the Marine Corps justice if given the opportunity to lead in the next rank.