As we enter the last two or three weeks of the Supreme Court's session, court watchers turn to a guessing game of which Justice has which opinion. What drives the guessing game are the informal rules of the court and two key pieces of data.
For the purposes of the guessing game, there are two key informal rules. First, opinions are assigned by the senior Justice in the majority (with the Chief Just being automatically senior to the eight Associate Justices). Second, in making assignments, the Justices are conscious of the work load of each of the chamber and try to keep the assignments relatively balanced. Of course, the alignment of justices on individual cases can frustrate this second rule.
The two key pieces of data are the opinions already issued by the justices and the number of cases argued (both for each sitting and the entire term). Not considering the two cases that were dismissed after argument, the Supreme Court heard 68 cases this year. Based on that number, each Justice should have seven or eight majority opinions. Furthermore, through January, there were 44 cases requiring opinions (with 24 between February and April). One would expect each Justice to have five opinions through January (one should have four) and two or three for the remainder of the term (and most likely to have two opinions from March and April given that there were 17 cases in those two months).
At the present time, Justice Kennedy has issued eight opinions. Based on the above, he should be done for the year (or at most have one more). There is also the quirk that, notwithstanding the above, Scalia actually had six opinions through January.
Looking at January, with four cases outstanding, three Justices do not have an opinion from January -- Justice Breyer (three total through December), Justice Alito, and Justice Kagan (both with four total through December). Two other Justices have four total through January (the Chief Justice and Justice Sotomayor). Based on the above, I think that the Chief Justice is most likely to have the Noel Canning (recess appointment) case. Since becoming Chief Justice, Justice Roberts has tended to keep the biggest cases for himself. Of the other three cases, I can see Justice Breyer getting McCullen (the abortion protester case), especially if there is a consensus that the Massachusetts law was just a bit too restrictive. My hunch says that Justice Alito is likely to get Harris (the home health care provider unionization case).
In February, with two cases outstanding, the three strongest candidates to have the opinions are the Chief Justice, Justice Thomas, and Justice Ginsburg. My hunch says that the Chief Justice has the Climate Change cases. The other case (involving Haliburton) involves the basic theory of security fraud. If the Supreme Court is not making a major change, Justice Ginsburg will have the opinion (which will be her eighth of the term). If the Supreme Court is making a major change, Justice Thomas will have the opinion.
There are still too many undecided cases from March and April (11 total remaining with six opinions issued) to make any firm guesses (other than Kennedy not having any and Ginsburg or Sotomayor -- both already at seven opinions -- maybe not having any). For the reasons noted above, my hunch says that the Chief Justice will have kept Hobby Lobby (contraceptive coverage) for himself.