The times that I recall this ability being used, the player's is losing heavily
This.
Almost everytime I used this ability it turned a clearly lost game into an clear victory.
However in a recent match I was on the receiving end of this ability. Enemy had only 50 points left. We about 450. He pulls off a "close the pocket" and destroys 3 T 34/85, one Katjuscha and multiple infantry squads ( and also troops of my allies)