The King of Fighters XIII/Game Elements/Guard Meter
Located just below the health bar on both players' sides is the blue Guard Meter. When blocking normal and special moves, the bar lowers accordingly to the blocked attack. Block too many hits and a player enters a Guard Crush state which gives the opposing player time to run in for a full combo. When approaching a Guard Crush, the Guard Meter flashes red indicating the need to get get away or start an offense. After a second of being out of blockstun, the gauge begins to refill itself automatically. Also note that blocking Desperation Moves and Neomax moves will NOT deplete the Guard Meter.
Characters have different lengths of Guard Meter, so for some characters it takes more hits to get guard crushed than others.