During each of our 30 linear impact tests we note whether the lower face cover has unlatched or unlocked during the impact. The number of times the faceguard remains fully locked after each of the linear impacts is expressed as a percentage for the latch rating. For example, if the lower face cover stayed completely shut in every one of the thirty impacts the score would be 100% but if it should open on nine occasions, the score would be 70%. We are not currently able to apply an objective measure to the safety effect of a failure of the chin bar locking mechanism and therefore we do not factor this into the safety (star) rating.