关门捉贼
Stratagems of Contending · 混战计Cut off the enemy's escape routes. Ensure total victory by eliminating all avenues of retreat.
In the Battle of Changping, Bai Qi surrounded the Zhao army completely and cut off all supply lines and escape routes. With no possibility of retreat or reinforcement, the Zhao army of 400,000 was forced to surrender.
Apple's App Store creates a "closed door" for developers — once invested in iOS development, switching costs are enormous. Users are similarly trapped by purchased apps and iCloud data. Both doors are shut; the "thief" (user/developer) cannot easily escape.
Soviet forces completed a massive encirclement of the German 6th Army at Stalingrad, cutting off all supply lines and escape routes. With no possibility of retreat or reinforcement, the surrounded army was forced to surrender.