zero in

The phrase possibly comes from adjusting a sighting mechanism of a firearm to minimise the discrepancy between where the sight points and where a bullet lands on a target. Another possible source is the Cartesian coordinate system in mathematics. In the coordinate system, points are defined relative to an origin (point of reference) labeled O, which has an (x,y) coordinate pair of (0,0).

• "At the spring sale, everyone zeroed in on the bargain clothes."
• "With 79 minutes gone, the most celebrated team of the modern age had been reduced to bunch of mooching, stumbling yellow-shirted spectators. A Champions League season that had seemed to be zeroing in on another coronation for Lionel Messi had been wrenched, gleefully, the other way."