WARREN BURGER'S Supreme Court is weighting the scales of justice against criminal defendants.

Analysis of the Burger court's rulings has focused too heavily on the words in the justices' opinions, which cast a fog of moderation over the court's clear anti-defendant bias. What has been overlooked is the way the Burger court, using discretionary powers little understood by the public, picks and chooses among the cases that come to it for review in order to shape the result.

Over the last 15 years, responding to pressures to reverse what some perceived as the liberal excesses of the court under Chief Justice Earl Warren, the Burger Court has been steadily giving police and prosecutors wider latitude to pursue criminals. But the court has actually gone farther than many lawyers and the public realize.

A look at the court's performance in the last term shows a clear bias not only in the outcome of cases, but in the selection of those the court will hear:

Federal prosecutors, seeking reinstatement of convictions reversed by lower appeals courts, were granted a review by the Supreme Court almost every time they asked for it. In every case where the court granted review, the convictions were reinstated.

In contrast, only a tiny fraction of 2,000 appeals brought by defendants were granted a review. In only two of those cases -- one-half of 1 percent of the defendants cases coming to the court -- did the court rule in the defendant's favor.

Taken together, state and federal prosecutors were able to obtain a hearing by the court at a rate 50 times greater than defendants.

This pattern shows the court is shaping the final outcome of its decisions by manipulating its power to pick its own cases. The winner of any criminal appeal can be so confidently predicted that it is clear the court makes up its mind well before briefs are submitted and arguments heard. The eventual words in the court's opinions, so carefully picked apart by scholars, lay little more than a patina of judge-like reasoning over the court's prejudgments.

At the beginning of every new term, the justices sort through some 4,000 cases. By far the largest source of petitions to the court is indigents who can't afford to pay the court's usual filing fee or to professionally print their legal briefs. Most of these "pauper's petitions" are filed by prisoners trying to overturn their convictions.

Under Chief Justice Earl Warren, these cases, often beginning with hand-scrawled, half-literate letters, were frequently reviewed by the court and became an important means for extending legal rights to the poor. For example, Clarence Gideon's pauper's petition from a Florida jail cell to the court became the 1963 landmark of Gideon v. Wainwright, establishing the right of indigents to counsel in felony trials.

In the last two years, the Burger Court has accepted fewer than 1 percent of these pauper's petitions -- one-sixth the rate of review in the later Warren court years.

For the term ending last July, the Burger court was twice as likely to grant review to criminal defendants who could afford the legal filing fee as it was to indigent defendants. That is far below the Warren Court's comparable statistics.

Prosecutors have always enjoyed better success than defendants in getting their appeals heard by the Supreme Court. But the ratio in the late Warren years was only about 10 times better for prosecutors than for defendants.

It is not for lack of significant legal issues that the court grants review so seldom to defendants. For instance, it is still perfectly legal for a prosecutor to strike potential jurors simply because they and the defendant are both black. Last term three black defendants, facing the death penalty, asked the court to look at the issue. The court declined.

Two other defendants had undisputed evidence that the forewoman of the jury that convicted them was so drunk during deliberations that other jurors tried to have her removed. The court also declined review. Still other defendants were denied review where there was serious misconduct by the prosecutor at trial, or utter lack of preparation by a defendant's own lawyer.

On the other hand, when prosecutors have asked, the court has gone out of its way to grant review in cases of obscure legal interest. For example, the court has agreed to decide whether a motor home is more like a car or a house for purposes of search and seizure. It will also decide whether a defendant wounded in a robbery can be forced to have a bullet surgically extracted from his shoulder for evidence.

Even the government's top criminal lawyer before the Supreme Court, Deputy Solicitor General Andrew Frey, says most of the pending cases "don't amount to a hill of beans."

Before the Warren era, the court was content to let lower courts, especially state courts, decide what procedures were due to defendants. The Warren Court actively fostered basic fairness to defendants, extending such rudiments as the right to a lawyer, the right to discover exculpatory evidence held by the prosecutor, the right against double jeopardy and the right to be informed of one's rights. By busily tunneling exceptions to these rights rather than overruling them wholesale, the Burger Court has maintained a mirage of moderation in individual cases that vanishes when one sees the pattern as a whole.

In exercising its discretion in choosing cases and in the way it decides the cases it chooses, the Burger Court is sending out a clear message to the courts that try criminal cases and hear their appeals: unless it is absolutely clear (and it rarely is) that a defendant's rights have been violated, a lower court can uphold a conviction and be confident that its decision is final. But courts that rule in favor of defendants do so at the peril of Supreme Court review and reversal.

This message has not been lost on reversal-sensitive lower courts. In the federal appeals courts in 1968, in the waning days of the Warren Court, 16 percent of all criminal convictions were reversed (a figure, by the way, belying the common misconception that courts in those years turned defendants loose at the drop of a gavel). Latest data from the federal court system show that figure to have been cut in half.

Winston Churchill once remarked that the ultimate test of a society is its criminal justice system. Criminal defendants make up our poorest, most powerless, most despised minority. Being tough on crime is one thing. Weighting the scales against criminal defendants is something else.