not give A cancer. The harm A suffered is the loss of a more favorable outcome. •But had D diagnosed A correctly, A’s chances of a more favorable outcome were <50%. A cannot establish as a matter of probability that D’s malpractice caused the harm. •Traditional approach: All-or-nothing; probability-driven. If π can prove deprivation of >50% chance, π recovers full value of harm. •Reactionary all-or-nothing approach: If π proves a loss of chance (some jxs: any; others: substantial) caused by D’s negligence, π recovers full value of harm •Value-of-lost-chance approach (emerging majority): π recovers even if <50% chance of better outcome, but only receives the value of the lost chance.