As we saw this term, by late May the Supreme Court begins releasing the bulk of its merits decisions, and with it a familiar guessing game starts among court watchers. If Justice Elena Kagan has not yet written from the December sitting (that is, the cases argued that month), or Justice Neil Gorsuch has already written twice from cases argued in March, observers begin to infer who may be holding the remaining opinions. The guesses rest on a widely shared assumption about the court’s internal practice: for the sake of fairness, the justices tend to receive roughly equal numbers of majority opinions from each oral-argument sitting.
That assumption has a basis in the court’s institutional structure. When the chief justice is in the majority, he assigns the majority opinion, and may seek to be as fair as possible. When he is not, the assignment falls to the senior-most justice in the majority. That assignment power is one of the court’s most consequential internal tools. The opinion author does more than announce the result. The author frames the reasoning, manages the breadth of the decision, and often determines how easily the opinion can hold together the coalition that voted for the judgment.
Scholars have long studied this power. Elliot Slotnick described an “equality principle” in majority-opinion assignment and traced opinion assignment practices from Chief Justice William Howard Taft through Chief Justice Warren Burger. Later work by Sara Benesh, Reginald Sheehan, and Harold Spaeth found that the equal-assignment norm has real force, while also leaving room for strategic behavior. Forrest Maltzman and Paul Wahlbeck likewise showed that opinion assignment in the Rehnquist court could reflect strategic considerations. Linda Greenhouse later applied this line of inquiry to Chief Justice John Roberts’ self-assignments, emphasizing how much institutional meaning can be packed into the chief’s choice to keep an opinion for himself.
This piece builds from that literature but focuses on a more specific practice: equality within each oral-argument sitting. The court hears merits cases in monthly sittings, generally running from October through April. The public authorship puzzle usually develops sitting by sitting. A justice who has not written from January is not simply behind for the term; that justice may be missing from a particular batch of cases argued together, assigned together, and often released in overlapping waves.
The data here, based on the Supreme Court Database, cover signed argued majority opinions from the 1946-47 term through the 2024-25 term, paired with vote-level information on which justices were in the majority. That vote-level layer is important because a justice cannot receive a majority-opinion assignment in a case where that justice dissented. So a sitting may look imbalanced in raw authorship counts even when the apparent gap reflects majority participation rather than a departure from the assignment norm.
The analysis asks three related questions. First, how consistently has the court distributed signed majority opinions within each argument sitting? Second, has that pattern changed in the Roberts court and in the years since Justice Amy Coney Barrett joined the court six years ago? Third, when the sitting-level pattern breaks down, does the explanation appear to be docket structure, majority opportunity, close votes, important cases, or the identity of the assigning justice?
Measuring the norm sitting by sitting
To start, the graph below tracks this assignment norm over time.
The graph above shows how the sitting-level norm is real, but conditional. It operates most clearly when the docket is small enough to permit rough equality and when most justices are regularly available to write for the majority. It becomes harder to maintain when majority coalitions vary across cases, when the chief justice is outside the majority, or when a sitting contains multiple high-stakes cases that may call for particular authors.
Across complete terms from 1946 through 2024, only about 28% of October-through-April sittings were balanced with each justice writing one majority opinion. In other words, the court has never operated under a mechanical rule that every justice must receive and write one majority opinion from every sitting. The norm is more flexible than that, and the historical record shows many sittings where some justices wrote multiple majority opinions while others wrote none.
The most striking historical change in the data comes with the Roberts court. From the 1946-47 term through the 2004-05 term, only 17.4% of argument sittings were balanced within one majority opinion. In the Roberts court, from the 2005-06 term through the 2024-25 term, that figure rises to 59%. At the same time, the average author range also falls sharply, from 2.49 opinions per sitting before Roberts to 1.42 during the Roberts court; that is, the court is taking on far fewer merits cases.
That shows a large institutional shift. The court did not suddenly adopt a written rule requiring equal distribution by sitting. But the practical pattern changed. Under Roberts, the court has far more often ended a sitting with each justice clustered near the same number of majority opinions.
The smaller modern merits docket likely explains part of the change. Earlier courts regularly produced more signed argued opinions from a sitting, which made perfect or near-perfect distribution harder. If a sitting produced 15 or 18 signed opinions, some spread among authors was almost unavoidable. A modern sitting with only seven, eight, or nine signed opinions gives the assigning justice a simpler path to rough equality.
This is also important for how we understand the chief justiceship. Roberts is often discussed in terms of public legitimacy, institutional rhetoric, or the ideological direction of the court’s merits decisions. Opinion assignment provides a different measure of institutional management. Whatever the ideological divisions in the cases themselves, the Roberts court has been unusually regular in distributing majority-writing work by sitting.
If the Roberts court is the period in which the sitting norm is most visible, then deviations during the Roberts years deserve closer attention. They may reveal the conditions under which the norm gives way: uneven majority participation, close votes, important cases, or moments when the chief justice is not in the majority and the assignment power shifts to another justice.
The Barrett era
Justice Amy Coney Barrett’s arrival in 2020 created the current six-justice conservative majority and changed the stakes of many of the court’s merits decisions. If ideological intensity were enough to disrupt the sitting-level assignment norm, the post-Barrett court would be the natural place to look.
The data show a more complicated picture. From the 2005-06 term through the 2019-20 term, before Barrett joined the court, 61.5% of Roberts court sittings were balanced within one majority opinion. From the 2020-21 term through the 2024-25 term, that figure fell to 51.4%. That is a meaningful decline, but it is not a collapse. The average author range for majority opinions barely changed: 1.41 before Barrett, compared with 1.43 in the Barrett era.
That finding complicates the expected story. The Barrett-era court has issued some of the most legally and politically consequential decisions in recent decades. But the internal practice of distributing majority opinions by sitting appears to have remained broadly intact. The court’s merits outcomes changed more dramatically than its sitting-level authorship pattern.
Vote splits, case salience, and the limits of the norm
But what can this tell us about strategic assignments from the chief justice or the senior most associate justice in the majority? The strongest version of the strategic-assignment hypothesis begins with close cases. When the court divides 5-4 or 6-3 along recognizable ideological lines, the identity of the opinion author can matter a great deal. The author may need to hold a fragile coalition together, choose how broadly to write, or decide how aggressively to move doctrine. If several such cases come from the same sitting, equal distribution may become less important than assigning the right opinion to the right justice.
The data does not show a simple relationship between close votes and sitting imbalance. In the Roberts court, sittings with more one-vote cases are not automatically more imbalanced in raw authorship range. That suggests that vote split by itself is too blunt a measure. A routine 5-4 case may put less pressure on the assignment norm than a landmark case decided by a wider vote. Conversely, a unanimous case may still be important enough for the chief justice to keep or assign the opinion author deliberately.
Given close votes alone do not appear to explain when the sitting norm bends, the more promising theory is interactional: deviations become more likely when close votes, legal importance, and majority-opportunity constraints converge in the same sitting. That is also the theory most consistent with how the court works. Assignment is not a numerical exercise performed after the term ends. It is a case-by-case choice made inside a specific majority coalition.
The assignment norm also depends on who is doing the assigning. The chief justice assigns the majority opinion when he is in the majority. When he is not, the power moves to the senior-most justice in the majority. That shift matters because it usually occurs in a distinctive subset of cases: cases where the chief justice disagrees with the court’s judgment or reasoning.
In those cases, assignment authority may pass to a justice with a different institutional role, different ideological commitments, and different incentives. During the Roberts court, a non-chief assignment often signals that Roberts was outside the majority. That fact alone makes the case unusual. The assignment choice then becomes especially revealing because it is made by a senior associate justice within a coalition that excluded the chief.
The aggregate data suggest that sittings are generally more balanced when the chief justice assigns all or nearly all of the majority opinions. That finding deserves some qualification though. Non-chief assignments are not randomly distributed across the docket. They arise when the chief is outside the majority (last term, he was in the majority in 95% of cases), which often means the case is more ideologically unusual or coalitionally unstable. Still, the pattern is important. The equality of opinion norm may be easiest to maintain when one assigner controls most of the sitting and is committed to managing the court’s workload across all nine chambers.
Non-chief assignments raise a different possibility. A senior associate justice assigning from within a narrower coalition may care more about preserving that coalition or shaping the doctrinal direction of a particular case than about sitting-wide equality. That does not mean non-chief assignments are improper or even unusual. It means they are the places where the assignment norm is most likely to reveal the interaction between internal procedure and substantive disagreement.
What this all means
The Supreme Court’s opinion-assignment practices are usually invisible to the public. Authorship is visible only at the end, when the court releases an opinion. But the pattern of authorship across argument sittings offers a way to study one of the court’s most important internal norms.
The data show that sitting-level equality has become much more common in the Roberts court than in the earlier modern court. The post-Barrett court has not abandoned that pattern, even as its merits docket has produced some of the most ideologically salient decisions in recent years. The more interesting story lies in the exceptions: sittings where authorship diverges from the expected pattern.
Those deviations should be understood in different ways. Some are products of docket size. Some reflect majority opportunity, because a justice who is not in the majority cannot receive the majority opinion. Some arise when the chief justice is outside the majority and assignment power shifts to a senior associate justice. And some may reflect the strategic assignment of important or closely divided cases to particular authors.
The sitting-level norm therefore provides a useful way to see the court as an institution. It shows the court managing workload, preserving collegial regularity, and sometimes adapting that to forming coalitions.
Recommended Citation: Adam Feldman, The Supreme Court and the opinion-assignment guessing game, SCOTUSblog (Jul. 13, 2026, 10:00 AM), https://www.scotusblog.com/2026/07/the-supreme-court-and-the-opinion-assignment-guessing-game/