Play the Player?

i know what play the board is, what means 'play the player' ??? 

thank you very much 

Basically, trying to maneuver a game to a position where your opponent is uncomfortable. Being able to do that usually requires you to know enough about your opponent where you can have that insight to begin with.

A guy at club tell me today that it mean take risks you donnot normal take against a weak player.  Is true??  

That is one interpretation... but it's asking for trouble.

It's better to consider the board first, and the the player second.

If you have a choice between a few moves which all seem equally good, THEN play the move which will give your opponent the most trouble due to their preferences, dislikes, areas of weakness etc.

Don't deliberately make a bad move just because your opponent will respond to it incorrectly.

Playing the board means playing the absolute best move (or so you think).  Playing against the player, almost by definition, means not playing the absolute best move, but that doesn't necessarily mean it's a bad move.

A strong player may choose to exchange Queens and enter a drawish endgame against a weaker foe.  Keeping Queens may be objectively the stronger move, but it gives the opponent more chances to land a tactic and win with a cheapo.  By exchanging Queens, the stronger player reasons he can outplay the other in the endgame, where most lower-rated players are notoriously weak.

This idea is very common in openings.  Many strong players will offer gambits to lower rated ones.  The only thing worse than an amateur's endgame is an amateur's defensive acumen.  Another example, if you know your opponent is an expert in the Najdorf Sicilian, it makes sense to play the Closed or Alapin or Bb5+ variation instead.

In my experience, playing the board has given me far better results.  If I worry about what my opponent may or may not be thinking, then I'm already giving him an advantage.  He is calling the shots without even needing to make a move.  Just play like game.  This may change at the higher levels, but where we are, play the board.

thank you very  much everyone!