**Stolen from the net:
VPIP (sometimes written as VP$IP) refers to the percentage of pots a player
voluntarily
puts money
in the
pot. If a player’s VPIP is 40%, that means that he puts money in preflop 40% of all
hands he’s dealt. VPIP doesn’t tell you whether a player raises or calls (raises and calls are lumped together); VPIP simply
tells you how often a player puts money in. A player with a high VPIP is loose, and a player with a low VPIP is tight.
PFR is a player’s
pre
flop
raising percentage. A player with a high PFR is more aggressive preflop than a player with a low PFR preflop. The PFR statistic is misused in very similar ways to how the VPIP statistic is misused. First, PFR refers to preflop play only. Players who are aggressive preflop
tend to be more aggressive postflop, and players who aren’t aggressive preflop
tend not to be aggressive postflop; however, until you have evidence verifying that these trends hold for a specific opponent, using preflop statistics to extrapolate how someone will play postflop is a huge mistake.
**End of Theft
My GoogleFu is strong...