A rock is a rather tight player who rarely plays a hand (less than 20% of the time), and even when he does, will fold postflop to raises unless his hand is strong. In Hold 'em, a rock waits until he has a strong pocket hand (i.e. pocket aces or kings, A-K, high suited pockets) before betting into any hand at all.
Strategy against a rock:
1.-Up your aggression: A rock doesn't like to play big pots without the nuts, if you find yourself against a rock, up your aggression, the rock will usually fold to any aggression (unless they have a good hand), but do be careful, just because a rock checks that doesn't neccesarily means they have nothing at all, rocks are usually passive players, that means that they usually check and call bets rather than make them.
2.-Steal their blinds: Rocks tend to fold a lot pre-flop due to their tight hand range, they're worried that someone else will have a better hand than theirs, if they're paying the blinds, try to bet a significant amount, this will usually scare them off, and thus, this will make you some easy money without competition, but do be careful if they call it, that usually means they have a strong hand.
3.-Don't pay them off: If a Rock player suddenly starts making big bets and raises, that's an indicator of a strong hand, when this happens, unless you have a strong hand, immediately fold and dont call their bets, seriously, just dont pay them off, The rock isn't usually going to be bluffing when this happens, and even on the rare circumstances they do, It'll happen so rarely that it usually isn't worth it trying to find out if they are indeed bluffing.
4.-Don't slow play: Slow playing against a rock is a very bad idea, yes, if you bet they'll probably fold, but if you do have a monster hand, dont slow play against these guys, they'll usually just check you right back, if you want to keep a rock in a hand, make small bets so that the rock just cant resist calling, that'll usually make them pot commited.
The Rock's approach often minimizes their loss in cash games, but also minimizes the amount they can win:
- The Rock's opportunities to win are rare since the Rock plays fewer hands, and the times they do play, if they have missed their hand, they'll usually fold to any bets
- Players who successfully read a rock will fold when the rock bets (unless they have a strong hand themselves), thus reducing the pot size.
At times you may find one or more "rocks" in play at a limit hold'em game. The rock is a number of chips equal to twice the big blind that are, usually, held together with rubber bands. The rock functions as a forced straddle. When the holder of the rock is to the left of the big blind he puts the rock out as a straddle. The winner of the hand will get the rock as part of the pot and will be expected to play it when he is next in straddling position.
The purpose of the rock is to loosen the game up and to increase the stakes without formally changing the limit.