WILKINS, J.

On June 6, 1987, shortly after midnight, William Hauck, travelling with his wife and two young sons, fell asleep at the wheel of an automobile on the Hutchinson River Parkway in New York City. The vehicle struck a light pole. Daniel, aged two years, who had been sitting in the back seat of the vehicle in a "booster seat" manufactured by the defendant, Cosco, Inc., died as a result of the accident. Daniel's mother, in the name of his estate, brought this action asserting that the booster seat had been defectively designed and had failed during the collision, causing Daniel's death by allowing his head to strike the seat in front of him.

The jury returned a verdict for Cosco, finding in an answer to a special question that "the condition of the booster seat at the time of the collision [was not] a substantial cause of Daniel Hauck's death" (emphasis in original). The jury were unable to decide whether the booster seat was reasonably fit for its intended use. In her appeal, which is here on our allowance of her application for direct appellate review, the plaintiff objects to two evidentiary rulings. First, the judge permitted Cosco, over the plaintiff's objection, to offer evidence that the father's insurer had paid $350,000 to the plaintiff in settlement of a claim against him. The judge rejected the plaintiff's contention that he had discretion to exclude evidence of the settlement. Second, the plaintiff was unsuccessful in obtaining a pretrial ruling excluding evidence that the father had consumed alcoholic beverages at his sister's home in Connecticut a few hours before the accident. The judge recognized that it was irrelevant whether the father's consumption of alcohol was a contributing cause of the accident. He ruled, however, that evidence of the father's alcohol consumption would be admissible on cross-examination as bearing on the credibility of aspects of his testimony. We affirm the judgment.

1. The judge correctly ruled that the defendant was entitled to place in evidence the amount of the settlement entered into between the father and the estate of the deceased child. "In mitigation of damages, a defendant is entitled to show in evidence the amount of money paid or promised to the plaintiff by a joint tortfeasor on account of the same injury." Tritsch v. Boston Edison Co., 363 Mass. 179, 182 (1973) ( Tritsch I). Evidence of such a settlement is, however, inadmissible on the issue of the defendant's liability. See Murray v. Foster, 343 Mass. 655, 660 (1962). When the Tritsch case came before us again, we noted that we had held that "evidence of payments received in settlement would be properly introduced to limit the possible recovery against [the defendant]." Boston Edison Co. v. Tritsch, 370 Mass. 260, 261 (1976) ( Tritsch II). In Franklin v. Guralnick, 394 Mass. 753 (1985), after quoting the language set forth above from our first Tritsch opinion, we added that "[n]othing we decide here undermines this long-standing principle concerning the introduction of settlement agreements in evidence at trial." Id. at 755. See Carota v. Johns Manville Corp., 893 F.2d 448, 451 (1st Cir.), cert. denied sub nom. Carota v. Celotex Corp., 497 U.S. 1004 (1990). In the Guralnick opinion, there is a strong intimation that, if a settlement is made during jury deliberations, any remaining defendant is entitled, on request, to a jury instruction as to the terms of the settlement agreement. Id.

Although our practice has been to follow the so-called "jury rule" under which, on a defendant's request, the judge must admit evidence of both a settlement and its amount on the issue of damages, it is a minority position and one that we abandon prospectively in favor of the so-called "court rule." When there is no significant risk that the jury's factfinding function will be distorted, evidence of the settlement should be excluded. See D.P. Leonard, Selected Rules of Limited Admissibility, The New Wigmore § 3.7.5, at 3:100 (1996).

For the future, unless admission of the evidence is relevant for some other purpose, no evidence of a settlement or the amount of the settlement shall be admissible. The judge shall instruct the jury to determine the damages that the defendant substantially caused, and the judge shall make the appropriate reduction in the amount to be awarded to a plaintiff if the jury return a plaintiff's verdict. See Tritsch II, supra at 265 (concerning method of reflecting settlement with one tortfeasor in judgment to be entered against another tortfeasor). There may be situations, however, in which evidence of a settlement, or the amount of a settlement, will bear on some issue in the case other than damages, and an automatic rule of exclusion should not be applied. In the judge's discretion, it may be fair in particular circumstances, as, for example, when one defendant settles during trial, to advise the jury of the fact that there has been a settlement and to instruct the jury to arrive at any damage determination without consideration of, or speculation about, the settlement. See Rule 408 of the Proposed Massachusetts Rules of Evidence which expresses the principle that we now adopt, by generally excluding evidence of a settlement to prove either liability or the amount of a claim but not requiring exclusion when the evidence is offered for another purpose.

The rule we adopt will tend to encourage a plaintiff to settle with one tortfeasor, knowing that the case against another tortfeasor will not be prejudiced by evidence of the settlement. Moreover, leaving the calculation to adjust for the settlement to the judge instead of to the jury, will facilitate the application of the offset that this court has directed be made to reflect a settlement with another joint tortfeasor. See Tritsch II, supra.

2. The judge did not abuse his discretion in ruling admissible evidence that the plaintiff's husband had consumed alcoholic beverages a few hours before the accident. See Commonwealth v. Sherry, 386 Mass. 682, 693 (1982). AS it happened, evidence of the husband's consumption of three alcoholic drinks was introduced only during the plaintiff's direct examination. It was no doubt offered then to mitigate the stronger negative impact that the development of that evidence would have had during cross-examination. We shall assume that the issue of the husband's drinking was not waived in such a circumstance.

The husband testified that he strapped Daniel in the booster seat when the family left his sister's home. Evidence of his alcohol consumption was probative as to the accuracy of his perception whether he put Daniel in the booster seat with the seat belt properly placed. See Commonwealth v. Carrion, 407 Mass. 263, 273-274 (1990). The admissibility of the evidence was within the judge's discretion.

Judgment affirmed.