If you're planning to burn the midnight oil for just one segment of the weekly 1987 World Chess Championship show (12:30 a.m., Channel 26), tonight may be the night. The primary topic is Game 16 -- so far, the most exciting and dramatic in the match, which was played last Monday in Seville, Spain.

The hour-long show, working with diagrams, commentaries and computer projections developed by a program called Chess Master 2000, recreates some of the slow-building excitement that spectators feel as they watch a game unfold. And the comments of expert (but hardly infallible) observers help to bring the viewer inside the minds of players poised in anxious uncertainty before a bewildering choice of moves.

To relieve the pressure of single-minded concentration on one game, the show breaks off into little special features, one on women in chess (will the best women players ever be equal to the best men?), another on the dozens of available variations on chess-as-we-all-know-it, and an elementary lesson with an audience-participation quiz on a basic element of chess tactics, this time the queen fork.

The question of women in chess is closely linked to the perennial question of heredity vs. environment. Chess has long been a stronghold of male chauvinist piggery, but as the restrictions on women's aspirations are eased, their performance in the upper levels of the chess world is improving notably. Still, there has never been a woman player who even came close to the world championship.

One of this week's panelists, U.S. women's champion Anna Akhsharumova, believes that it is only a matter of time before a woman takes the world championship, and moderator Shelby Lyman agrees. Victor Korchnoi, the perennial runner-up for the championship in the 1970s, observes that women are "catching up every year."

A somewhat different view is taken by present and former champions. A woman winning the world championship is "impossible," according to former champion Mikhail Tal, "because you have to be quiet for five hours." Current champion Gary Kasparov is as categorical and less witty: "Men have superiority in many areas, and chess is one of them."

Anatoly Karpov, former champion and current challenger, is a bit more nuanced: "Maybe their nervous system is not so good for chess as a man's, but I think they have the same ability to play chess on the same level as a man."

Meanwhile, in the background, a demonstration board shows the ups and downs of Game 16, along with numerous variations suggested by panelists but not actually played. Besides Akhsharumova, this week's panel includes grandmaster Edmar Mednis and two young players, Julia and Jeff Sarwer, who have both held the world championship for children under 10.

The shows are not taped until after the game is over, but the participants are honor-bound not to look at the game before the show, which starts at a point well into the middlegame. This ensures spontaneity, as well as a number of charming mistakes, in the comments. The viewer who has already read about the game can observe with the advantage of hindsight and feel superior to the experts -- for example, when Jeff Sarwer suggests a pawn move that was actually played and that led to Kasparov's downfall.

Lyman has been producing shows about championship chess since the Fischer-Spassky match in 1972. In the early years, these shows were of interest almost exclusively to hard-core chess fans, but this year, using the facilities of New York's city-owned Channel 31, the show's technical quality makes it apt for a much wider audience.