An overbet is a bet that is significantly larger than the current size of the pot. This concept does not exist in fixed-limit or pot-limit games, since the betting sizes are limited to at most the size of the pot.
In no-limit games, bets are generally made in relation to the current size of the pot, depending on the amount of odds the bettor wants to lay for potential callers. Typical bets are half the size of the pot (to lay a caller 3-1 odds), or the size of the pot (to lay a caller 2-1 odds).
Bets that don't fall into the half-to-full-size-of-the-pot range are either underbets or overbets, though bets just outside the range are still considered normal (e.g. a bet of $10 into an $8 pot is not generally considered an overbet).
Overbetting is usually done for one of two reasons:
- Players who are bluffing may choose to overbet the pot in order to make it that much less likely that anyone would call.
- Players with a very strong hand may overbet the pot in order to:
- make it seem as though they are bluffing, and overbetting according to the first point, or:
- make the maximum amount from a caller who is certain to call any bet, but is also certainly beaten.
Overbetting aimlessly is generally considered poor strategy, for a few reasons:
- If you are bluffing, any caller who could call (for example) a bet that is the size of the pot, could probably also call a bet that's twice the size of the pot. If your bluff is going to succeed, it would succeed with the same frequency, but you would risk fewer chips.
- If you have an extremely strong hand (for instance, the absolute nuts), and overbet the pot, you may scare out potential callers who could call smaller bets. If you are guaranteed to win anyway, why not win more chips as you do so?
As an example, a player who has pocket kings is up against two players with unknown hands. The flop comes K-9-4 rainbow. The pocket kings have the absolute nuts at this point and have no obvious draws out against them. It is wise for the kings to check or to bet normally, perhaps a half-pot-sized bet, to induce other players to call with their worse hands. If the pocket kings were to overbet the pot here (for example, going all-in with $1000 for an $80 pot), they could only be called by players holding 9-9 or 4-4, and perhaps not even then. The Kings, however, should want to encourage calls from players who hold A-K, 9-8, 9-4, or other moderately powerful hands, to try to build the pot and win more money. Such hands are essentially drawing dead against the Kings at this point, so any extra money they can get into the pot is theirs to win.
Overbetting can be solid strategy if:
- If you are almost certain that you have the best hand and you are almost certain that one or more players will call your overbet, you make more money by betting more. However, you must be extremely confident of both facts. If you are wrong about either one, you cost yourself a significant amount of money (and may even lose it all!)
- If you are almost certain you have the worst hand (or that there is one better hand out there) and you are very confident that only a bet of this particular size will get your opponents to fold, and that a smaller bet will definitely be called, then the overbet is the proper amount to bluff. When you bluff, you want to make sure that you are betting the smallest amount necessary to guarantee that no other player will call'.