Match? Reach? Probable?  Or...How do I know where I will get in?

Probable:

Typically a college where your SAT and grades are at the very top end of the admitted student range.  That is, your SAT scores are CR600, M600 and WR600.
For students admitted to that college, the middle 50% of students who are admitted have scores as follows:
CR450-550;  M450-550; WR450-550.  Most students admitted have roughly a B- average; you have a B+ average.  That college is a "probable" for you for admission.

Match:

A college where your SAT and grades are in the middle of the middle 50% of admitted students.  You can't count on admission to this college, but it's a solid 'target' or 50/50 chance.

Reach:

A college where your SAT scores and grades fall in the bottom 25% of the scores/grades reported in the middle 50% of admitted students.  This is a long-shot, or 25% chance or less.  Students should not be afraid to apply to 1-2 reaches, but it is extremely important not to apply to a 'top heavy' list of all matches/reaches.

4.5 is the ave number of apps a CA student files. 
Balance is the key! The college counselors work with students to be sure they have a balanced list with at least 1 "probable" about which they are excited; 1-3 matches; and 1 or so reaches.