MARKED BY the consensus feeling that being here is a hardship, but going home is worse, the WAC's annual postseason basketball tournament got under way today in Wyoming's Arena-Auditorium.

The one-loss-and-your-season-is-over tournament runs through Saturday night and the prevailing notion is that being an underdog this time of year isn't such a bad thing.Favorites are considered an endangered species at this event; the top seeds from the regular season might as well be strolling down Grand Avenue wearing a bullseye.

For example, on tournament eve, BYU Coach Roger Reid said, typically, "We've got our hands full with CSU because it's hard to beat any team three times." The coach was referring to the Colorado State Rams, a team his Cougars handled fairly easily both home and away during the regular season - winning by 17 points both times. Now, along comes the postseason tournament and BYU, seeded second (in accordance to its finish in the regular season standings), opens against the Rams, seeded seventh.

On the surface, it looks exactly like the the kind of game you'd like to have when opening your December classic. But this isn't December and the pressure is on and that tends to skew a lot of people's thinking, coaches' in particular.

The theory as expounded by Reid is that the team you walloped twice during the regular season is A) Good and mad, B) Plotting revenge, and C) At least five times as talented as it was during the regular season.

A lot of coaches this week are pointing to last year's tournament, when regular season champion Colorado State had an opener against No. 9-seed Air Force - and Air Force won.

And to the fact that in the past seven WAC postseason tournaments, the topseed has won exactly once - way back in the inaugural tournament in 1984, when UTEP was supposed to win and did.It all conspires to paint a gloomy, going-to-the-dentist kind of atmosphere as the WAC dangles its lone NCAA tournament-qualifying invitation as the carrot at the end of the week.

Even if there's no historical precedence for the downer mood.

The fact is, in the seven years the WAC has held its NCAA-qualifier, being a favored team hasn't been a bad deal at all. Favorites, for the most part, have acted like favorites, and underdogs have acted like underdogs.

There have been 55 games in the seven tournaments to date. Of those 55 games, 36 have been won by the highest-seeded team, 19 by the lower-seeded team. A favorite, then, has won 66 percent of the time, an underdog 34 percent of the time. And of the 19 times an underdog has won, 10 of those upsets have been when the teams playing have been within one seed of each other - a No. 2 seed beating a No. 1, for example.

Only three times in tournament history has a decided underdog come through - once in 1985, when No. 9 Air Force upset No. 5 BYU; and twice last season, when No. 7 Utah beat No. 2 BYU and, as mentioned, No. 9 Air Force beat No. 1 CSU.

As for the it's-hard-to-beat-the-same-team-three-times theory, the fact is, it isn't hard at all.

There have been 29 games - more than half of the alltime tournament total of 55 - involving a team that has swept the other team.

The sweeper has gone on to win the third game 21 times.

Statistically, a team that has been swept twice during the regular season has a 27 percent chance of winning when it faces its nemesis again.

Considerably more exposure is given to the event when an underdog avenges its regular season shutout - which probably accounts for the coaches' recurring nightmare.

The only prevailing horror story that can be both historically and statistically borne out for the WAC tournament is the difficulty of the No. 1 seed to go on to the title.

It has indeed happened just the once, in 1984, by UTEP. Traditionally, No. 2's have tried harder. Four second-seeds have won, as well as two teams seeded fourth.

However, it would seem that incentive has been the biggest reason for the downfalls of the top seeds, not the time of year or some kind of mystical role reversal. Top seeds are usually assured of an NCAA berth regardless of how they do at the WAC meet. Of the six No. 1 seeds that have failed to win the automatic berth at this tournament, five have nonetheless been invited by the NCAA anyway.

Such is the case this year with Utah, the WAC's regular season champ. No matter what happens here this week, the Utes will live to play again. As for the rest of the field, as the saying goes, the race may not always go to the strong and the mighty - but that's the way to bet.