IAM 20 years old. I have four years, eight months and 28 days to get married. After that, according to a recently released study by a team of Harvard and Yale sociologists, my chances of leading a life of marital bliss drop to an even 50 percent. If I postpone the happy day for five more years until I'm 30, and, hopefully, an up-and-coming corporate attorney, I'll have a mere 20 percent chance of tying the knot. By the time I'm 35, I can forget about marching down the aisle altogether, for I will have only a 5 percent chance of doing so.

Where has all the time gone? Apparently, all the hours I've spent in Widener reading up on the Revolutions of 1848 for my tutorial should have been devoted to scouring the Harvard campus and the world at large for the perfect mate.

LET'S SUPPOSE I started out at birth with a 100 percent chance of eventually putting a Mrs. in front of someone's name. And according to the figures presented by Drs. Bennett, Craig and Bloom, I'll pass my 25th birthday with a 50 percent chance of marrying. Divide those 25 years into the remaining 50 percent, and you come up with a decrease of 2 percent in the likelihood that I will get married for every year I grow older.

As I was carlessly coloring away my days in kindergarten, my chances of marrying were about 90 percent. In the sixth grade, when I spent Tuesday afternoons getting kicked by my unwilling partners in dancing school, they dropped to 76 percent. When I graduated from high school, they plummeted to 66 percent. It's a little disconcerting to find out that now, as I enter the third decade of my life, a total stranger has assessed my marriageability at a miserable 60 percent, just a shade better that a fenced 50-50. Now I know what the Princess of Wales felt like when London bookies were laying odds on the sex of the as yet unborn Prince William of Wales: 3 to 1 for a girl, 2 to 1 for a boy, 30 to 1 for twins, 100 to 1 for triplets, etc.

But then again, she was married and I'm not. The way I see it, I've got two, maybe three years left before I have to start heeding the tick of the statistical clock. By then, I'll just be starting graduate school. I can see it now, sandwiched between hours in the Law Library and reading up on torts in my room, I can schedule search and destroy sessions in which I'll telephone, write to, visit or similarly network all the eligible males of my acquaintance in the hope that one of them will finally crack. Actually, things might not be as black as they seem; after all, I hear that Dr. Bennet is still single, and mother always did want me to marry a professional man.