Table 2

True-positive, false-positive, assumed false-positive, false-negative definitions for the guided and unguided analysis (phase II)

	True-positive	False-positive	Assumed false-positive (off-camera)	Assumed false-positive (inactive)	True-positives	False-negative
	Guided analysis				Unguided analysis
iMG-triggered event	Impact reported	Impact reported	Impact reported	Impact reported	Impact reported	Impact not reported
Video footage	Video footage shows a visible HAE from a contact event at an iMG-triggered event timestamp.	Video footage shows that player does not have a visible HAE from a contact event at timestamp of iMG-triggered event.	iMG-triggered event occurs during active match-play while the instrumented player is on the field. The instrumented player is not visible on the video footage. Given the video footage is following play (ie, the ball, tackles and carries), it is assumed this is a false-positive.	iMG-triggered event occurs during half-time or during the 10 min period following full-time. Video footage is not available to confirm if a HAE occurred (eg, during sideline warm up tackles).	Instrumented player is involved in a one-on-one shoulder tackle, as the tackler.	Instrumented player is involved in a one-on-one shoulder tackle, as the tackler.