An expert or skillful person; someone good at a particular field (often used for players in games like shogi or go).
彼は囲碁の好手として知られている。
He is known as an excellent go player.
地元の大会には若い好手が何人も参加した。
Several young skilled players took part in the local tournament.
あの選手は技術が高く、間違いなく好手だ。
That player has high skill — definitely an expert.
A good or clever move (in games like shogi or go); a well-considered play that improves one's position.
最後の一手はまさに好手だった。
The final move was truly a brilliant one.
彼の好手を見て、対局の流れが変わった。
Seeing his clever move changed the flow of the match.
初心者には分かりにくいが、あれは好手だ。
A beginner might not notice it, but that was a good move.