Declarer: West; Myself: North
West has shown ♣ suit during the bidding auction. at least 4's.
Question?
Holding KJT95, what card should be leading in the middle of the game?
J or 9 or 5
How will I know he may have Ace or king higher than J to learn quickly with out taking much time?
J denies higher card for the leading suit even in the middle of the game, will it apply?

Help
