Literally: hundred – emit – hundred – middle
Alternately: Hitting the center of the target with every arrow or bullet fired. A 100% hit rate. Metaphorically, a person with plans or, especially, predictions that never fail.
Notes: This compound comes to us from the Zhan Guo Ce (『戦国策』, Sengokusaku, which we’ve seen before). The story goes that Yang You Ji (養由基, Japanese You Yuuki), a legendary archer from the state of Chu, walked a hundred paces from a willow tree and loosed a hundred arrows from his bow, striking a different leaf on the tree with each one.