Sammy Sosa slugged his 60th and 61st home runs this weekend, matching the legendary totals of Babe Ruth in 1927 and Roger Maris in 1961. The fanfare, however, is relatively modest, because the standards of home run achievement have been radically adjusted, by Sosa himself (66 in '98) and by Mark McGwire (70). Baseball pundits are divided about what it all means. Clearly we need to think about the meaning of statistics, and of numbers more generally - and should endeavor to avoid a mindless, medieval numerology, as epitomized by the widespread and inarguably mistaken assumption that a new millennium will begin with the arrival of the year 2000. Welcome to Sports Monday.

First, let's deal with the millennium, then pivot back to Sosa with the grace of a second baseman turning a double play even as the runner barrels into the base with spikes high. (This metaphor under construction.)

There are two distinct schools of thought: Ordinary people, who say 1999 is the last year of the century (and thus the millennium), and calendar weenies, who believe that the year 2000 is the last year of the 20th Century, and that the new millennium will begin on Jan. 1, 2001.

I'm firmly in the weenie camp. Being a calendar weenie is difficult, because people look at you as though you're a member of a cult, some sect of negativism whose organizing principle is the denial of the obvious. It's like advocating a return to the gold standard, or insisting that Shakespeare was secretly the Earl of Oxford, or being the local precinct chairman for Hatch 2000.

Most people think this millennial hand-wringing is weird and pitiful. There's not a chance in a zillion that they will fail, this Dec. 31, to shout "Happy New Millennium!`

We weenies are not denying the magic of the year 2000. We acknowledge that the coming of the year 2000, the rolling over of the odometer, is a huge event, surely a more satisfying moment than whatever it is that happens a year later. But let's call the coming new year what it is: The arrival of the year 2000.

The weenies have the Pope on their side, and after all, it is HIS CALENDAR. The Vatican solves the problem by doubling the celebrations. The Pope has declared the year 2000 a Holy Year to celebrate the Second Millennium (retrospectively) of the birth of Jesus. This Dec. 31 there will be, at St. Peter's Basilica, a prayer vigil leading up to the year 2000. A year later, on Dec. 31, 2000, there will be a prayer vigil "for the passage to the new millennium.` (Go to www.vatican.va/index.html.)

The designers and keepers of this calendar have never been wavering or ambiguous about when centuries end. If you look back at newspapers that published on Jan. 1, 1900, you'll see that the Pope announced a Jubilee year in celebration of the 19th Century then coming to a close. Not until a year later did he announce that the 20th Century had begun.

The explanation is as simple as counting to ten on your fingers. The calendar has never presumed a Year Zero. The presumption is that the Year One marks the first year of the life of Jesus. Thus you can count your fingers, moving your lips like a moron, and see that the final finger is number 10, a number that clearly ends with a zero and not with a 9. Thus a century does not end in the number 99, but in 00.

At the same time, this is obviously a losing battle, as I began to realize earlier this year when the copy editors of The Post allowed various writers to refer to certain annual events as the "last` of the millennium. The copy editors here are typically conservative, prudent and wise; and if they allow 1999 to be the last year of the millennium, then the weenie cause is lost.

So this December 31st, when the clock strikes midnight, I will just go with the flow. I'll shout, "Happy New [Mumble]!`

Now, back to Sosa.

He and McGwire are still hitting dingers at a pace never before seen. Their home run derby last year was genuinely thrilling. This year, the hype is missing, and it almost seems as though, with every home run, Sosa and McGwire diminish their previous achievement.

Is it fair to Sosa that, even as he becomes the first player to hit 60-plus homers twice, he still only rates a wire service story? Some baseball writers are appalled by the situation. But the fact is, statistics in baseball have meaning only in a context of general performance.

There is no innate significance in 60 or 70 or 80 home runs, nor in batting .400, the other great standard, which no one has reached for an entire season since Ted Williams hit .406 in 1941. Someone with scant knowledge of baseball might be shocked to find out that no one can hit safely twice per every five official at-bats.

The game has changed. The ball is wound tighter than Dennis Hopper. Home runs are as cheap in a ball yard as hot dogs and cold beer. What's startling, what really makes you sit up on the sofa and crank the volume on the remote control, is when you see someone lay down a bunt correctly and advance the runner from first to second. The unremarkable Cincinnati Reds one night hit 10 home runs in a nine-inning game. Atlanta's Chipper Jones has 41 home runs - and a good rule of thumb is that someone named "Chipper` should never be allowed to hit more than about 30.

Guys who can't even get dates, geeks, mouth-breathers - people who think the year 2000 isn't the start of a new millennium! - are launching balls 450 feet. It's not the end of the world, but it's definitely ominous.

Rough Draft appears Mondays, Wednesdays and Fridays except when banned by Papal decree.