野球

How it works

は (topic) raises 野球(やきゅう) (baseball) as the topic — “as for baseball…”. There's no verb at all: 得意(とくい) (good at) is a description that simply stands at the end, and rising intonation (marked here by ？) turns it into a casual question. The “you” being asked about is left unsaid, carried by context.