This ability is crucial at the early stages of the game.You can teleport your Stalkers every 10 seconds when they produced.This blink chance gives the player lots of defensive and offensive advantages.For instance you want to make an offensive move but your forces are not enough to defend your expansion or your base,here using Stalker will be wise to both attacking the enemy base  and defending your base at the same time.This ability can be used for improving your forces firepower at a sudden needed instant so as we can see this unit will be very critical for the destiny of the game.