W$WSF: Won Money When Saw Flop
Of hands where a player saw the flop, W$WSF is the percent where they won money. It includes cases where they went to the showdown and won as well as cases where everyone else folded.
If a player's has a high W$WSF, it could mean one of two things. It could mean they fold most hands before the flop (as indicated by a low VPIP); they tend to win when they see the flop because they only see the flop with a good hand. Alternately, the player is doing a great job of intimidating other players into folding. In that case, look for opportunities to catch their bluffs.
W$WSFper_hand: true opportunity: saw_flop instance: won > $0