It's basketball vs. suds vs. comedy in a major broadcast television battle as the season winds down.

CBS has the hoops, NBC has Danielle Steel and ABC uses a bunch of comedies from other nights of the week as the frontline troops in this war. (The three networks are neck-and-neck with just a few weeks left in the 1990-91 season, making the outcome all the more important to them.)The basketball game is, of course, the championship contest in the NCAA Tournament (7 p.m., Ch. 5). And, surprise of surprises, the game does not feature defending national champion Nevada-Las Vegas.

Ha ha ha, hee hee hee, ho ho ho, har har har. (Whoops. Sorry. That was uncontrollable glee over the Runnin' Rebels defeat at the hands of Duke in Saturday's semifinals.)

Anyway, Duke will take on Kansas for the title. (But it will be harder to pick a team without UNLV to root against.)

NBC, which found considerable success running Danielle Steel adaptations ("Kaleidascope" and "Fine Things") against baseball last fall, tries the same strategy again with the popular novelist's Changes (8 p.m., Ch. 2). Unfortunately, this movie is by far the weakest of the three.

Like all such projects, the actions swirls around fabulously rich, famous, beautiful people who nonetheless battle heartache on the way to the inevitable happy ending.

Cheryl Ladd stars as Melanie (Mel) Adams, an ambitious network newswoman and divorced mother of teenage twin girls. Michael Nouri is renowned and wealthy heart surgeon Peter Hallam, who meets and falls in love with Mel.

The problem is, Mel has been offered a big job in New York but Peter lives in L.A. So Mel gives up her career for love, leading to various complications.

We're treated (or is that subjected?) to teen sex, pregnancy, abortion, whining, screaming, crying and various other sudsy trials, many of which are so ludicrous they're laughable. ("Changes" is, however, quite chaste as these movies go - not much in the way of steamy scenes.)

The biggest problem is that Peter is such a cold fish it's hard to imagine that a cleaning woman would give up her career for him, let alone a network anchorwoman.

But this is, after all, a counter-programming effort aimed at female viewers who supposedly won't be interested in the basketball game. (And, for the record, my wife liked this movie a lot more than I did.)

And one note about NBC's ad campaign for the movie. Although the commercials make it appear there's some sort of dark secret and big mystery in "Changes," there isn't. Chalk it up to incredibly deceptive advertising.

Meanwhile, ABC borrows shows from Tuesday and Friday nights in an attempt to remain competitive. (And, because this is usually a strong night for CBS, it's apparent the alphabet network is no longer shooting to beat No. 1 NBC but is aiming to keep CBS in third place.)

Anyway, those six sitcoms are Full House (7 p.m., Ch. 4), Who's the Boss? (7:30 p.m., Ch. 4); Family Matters (8 p.m., Ch. 4), Baby Talk (8:30 p.m., Ch. 4), Coach (9 p.m., Ch. 4) and Anything But Love (9:30 p.m., Ch. 4). "Who's the Boss?" and "Coach" are reruns; the others air new episodes.

If neither basketball nor suds nor ABC sitcoms sound particularly attractive to you, there are several other good choices, including:

- Saturday Night Live Goes Commercial (7 p.m., Ch. 2): What, you say? "SNL" has always been commercial?

Well, this hourlong special refers specifically to the spoofs of television advertising the show has done over the past 16 years - everything from Dan Aykroyd's Bass-o-matic to Buckwheat (Eddie Murphy) selling his "Greatest Hits."

Think of it as a long series of commercials, interrupted by commercials.

- Desperately Seeking Susan (7 p.m., Ch. 13): This is the one movie starring Madonna that's different from all the others - it's good. The Material Girl co-stars with Rosanna Arquette and Aidan Quinn in this comedy about murder, mistaken identities, old-fashioned lifestyles and living on the edge.

- Shape of the World (9 p.m., Ch. 7): An interesting new six-part series from PBS about how the world has been mapped.

- Evening Shade (9:30 p.m., Ch. 5): Wood is faced with a couple of girls who want to join his football team.

- Moyers/The Arab World (10:35 p.m., Ch. 7): This series, which airs through Friday, takes a look at Arab history, culture and religion - something Americans know far too little about.- LOOKING TOWARD TUESDAY: A Schoolbreak Special (3 p.m., Ch. 5) titled "Abby, My Love" deals with a teen who is sexually abused by her father; the new live-action kids' series Harry the Dirty Dog (3:30 p.m., Nickelodeon) debuts; there's a double dose of Roseanne (7 p.m. and 8 p.m., Ch. 4); the Jazz try to win one in Phoenix in NBA basketball (7:30 p.m., Ch. 13); Triumph of the Heart: The Ricky Bell Story (8 p.m., Ch. 5) is a made-for-TV tear-jerker; and Law & Order (9 p.m., Ch. 2) deals with a kidney transplant in which the organ was illegally obtained. (Haven't we already seen this on both "L.A. Law" and "Knots Landing" this season?).