"In olden days a number of methods were used to ensure that juries reached a unanimous verdict. From the fourteenth through the eighteenth centuries, one “method of accelerating unanimity” was to prohibit jurors from eating or drinking until they all agreed on a verdict."

That's how Chief Judge Carnes starts out this entertaining opinion about deadlocked juries.  The entire introduction:

In olden days a number of methods were used to ensure that juries reached a unanimous verdict. From the fourteenth through the eighteenth centuries, one“method of accelerating unanimity” was to prohibit jurors from eating or drinking until they all agreed on a verdict. 3 William Blackstone, Commentaries *375. And if jurors did not unanimously agree on one before the judges left town, Blackstone recounted, “the judges are not bound to wait for them, but may carry them round the circuit from town to town in a cart.” Id. at *376. They were hauled around in the cart “until a judgment ‘bounced out.’” Renico v. Lett, 559 U.S. 766, 780, 130 S. Ct. 1855, 1866 (2010) (Stevens, J., dissenting). Which is to say until the resolve bounced out of the holdout jurors.
In one seventeenth-century sedition trial (involving William Penn and a co-defendant), the jury deadlocked on the most serious charge. George C. Thomas III & Mark Greenbaum, Justice Story Cuts the Gordian Knot of Hung Jury Instructions, 15 Wm. & Mary Bill Rights J. 893, 898–99 (2007). The judge responded by threatening to have a juror named Bushel branded unless the jury agreed that the defendants were guilty as charged. Id. at 899. When no verdict was forthcoming, the judge did not send for a branding iron, but he did have all the jurors “locked in the jury room without meat, drink, fire, and tobacco” until they could agree. Id. (quotation marks omitted). After nicotine withdrawal and the prospect of starvation failed to work, “the judge threatened to cut Bushel’s throat” if there were no verdict. Id. (Thus posing the prospect of a dead juror to unlock a deadlocked jury.) When even that threat did not bring forth a unanimous verdict, the judge gave up. Id. Bushel escaped the experience unbranded and with his throat intact, while the jury as a whole escaped with its disagreement intact. But the judge was angry enough at the jurors’ failure to agree that he fined each of them forty marks for their intransigence. Id. Fortunately, when the case made it to the Court of Common Pleas the fines were set aside. Id. at 899–900. History does not record if Bushel or any of the eleven other brave souls ever served on another jury.
Since those days, we have come a long way and now accept that some jury deliberations will end in deadlock. United States v. Rey, 811 F.2d 1453, 1460 (11th Cir. 1987) (“The jury trial system has not malfunctioned when the jury cannot reach a verdict. One of the safeguards against the conviction of innocent persons built into our criminal justice system is that a jury may not be able to reach a unanimous verdict.”). We no longer try to coerce holdout jurors to reach a verdict that they cannot abide. Or at least most of the time we don’t.

The opinion goes on to grant a habeas petition for ineffective assistance of counsel:

The jury that convicted our appellant, Sumnar Brewster, might feel some affinity with juries of yesteryear. Over the period of two days of deliberations the jurors repeatedly told the judges –– there was one judge on the first day of deliberations and a different one on the second day –– that they could not reach a unanimous verdict. And the judges repeatedly ordered them to keep trying. All told, the jurors sent six notes to the two judges stating that they could not reach a verdict.
Three times the jurors disclosed how they were divided: first reporting that they were deadlocked 9 to 3 for conviction, later that they were still deadlocked but now 11 to 1 in favor of conviction, and still later that the one holdout juror was continuing to hold out. Throughout the deadlocking, the judges gave a formal Allen charge, later two additional admonitions that the jurors must continue deliberating, and finally, another long charge that included instructions to keep on deliberating. That lengthy charge emphasized that the jurors had taken an oath to follow the law, which meant they must deliberate more. The judge ended his instructions with the challenge that he had taken his oath seriously and hoped they would do the same.
Shortly thereafter, when told that the one juror who wouldn’t vote to convict was doing crossword puzzles, the judge ordered all the reading materials taken out of the jury room. That tactic turned out to be even more effective than threatening to kill the hapless Bushel had been in William Penn’s case three hundred years before. Just 18 minutes after all reading materials were removed, Brewster’s jury dutifully –– and we do mean dutifully –– returned a guilty verdict. Through it all Brewster’s two attorneys neither objected nor moved for a mistrial. Not once.
This is Brewster’s appeal from the denial of his 28 U.S.C. § 2254 petition for a writ of habeas corpus. He claims that his trial counsel rendered ineffective assistance by failing to object, or move for a mistrial, at any point during the deadlocked deliberations.