What is the difference between probability of kill (Pk) and probability of individual hit (PHi) in gunnery?

What is the difference between probability of kill (Pk) and probability of individual hit (PHi) in gunnery?

• A. Pk is the probability a single shot hits the target; PHi is the likelihood of destroying the target.
• B. Pk is the likelihood of destroying the target; PHi is the probability a single shot hits the target.
• C. Pk and PHi are identical concepts.
• D. Pk relates to radar probability, PHi to manual aiming.

Answer: (B)

In gunnery, two different probabilistic outcomes are tracked: whether a shot lands on the target, and whether that landing actually destroys the target. Hitting is a prerequisite for a kill, but not every hit ends in destruction. The correct idea is that the probability of a kill is the chance that a single shot both lands and produces a lethal effect. So the probability of kill is the likelihood that the shot hits times the chance that a hit actually destroys the target (which depends on target vulnerability, damage state, and weapon effectiveness). If a hit is always lethal, kill probability would equal hit probability; more commonly, kill probability is smaller because some hits do not result in a kill. For example, if the chance to hit is 0.4 and the hit has an 0.8 chance of causing a kill, the kill probability is 0.4 × 0.8 = 0.32. This distinction clarifies why one term describes landing a hit and the other describes producing a destruction result. Chances that aren’t about hitting or killing—such as radar probability versus manual aiming—don’t define these terms. And the two concepts are not identical; they describe different stages of the lethality process.

In gunnery, two different probabilistic outcomes are tracked: whether a shot lands on the target, and whether that landing actually destroys the target. Hitting is a prerequisite for a kill, but not every hit ends in destruction.

The correct idea is that the probability of a kill is the chance that a single shot both lands and produces a lethal effect. So the probability of kill is the likelihood that the shot hits times the chance that a hit actually destroys the target (which depends on target vulnerability, damage state, and weapon effectiveness). If a hit is always lethal, kill probability would equal hit probability; more commonly, kill probability is smaller because some hits do not result in a kill.

For example, if the chance to hit is 0.4 and the hit has an 0.8 chance of causing a kill, the kill probability is 0.4 × 0.8 = 0.32. This distinction clarifies why one term describes landing a hit and the other describes producing a destruction result.

Chances that aren’t about hitting or killing—such as radar probability versus manual aiming—don’t define these terms. And the two concepts are not identical; they describe different stages of the lethality process.