What does half-pot-limit mean?

In half-pot betting the maximum bet is half of whatever is in the pot. In a head-to-head contest, HP pots and bets double with each additional bet or raise, so four bets or raises increase the pot by a factor of 2 x 2 x 2 x 2, or sixteen times. Pot-sized bets triple the pot, giving 3 x 3 x 3 x 3 or eighty-one times the original pot after four bets or raises, in a head-to-head contest.

Half-pot is the smallest of the big-bet games, and like its big brothers pot-limit and no-limit, it provides plenty of scope for using position and well timed bluffs to win with inferior hands, and the pot builds quickly when you are betting for value. At the same time the more moderate bet sizes mean that half-pot games last much longer than pot-limit or no-limit games with a given amount of money available. Half-pot games are much easier to keep alive than pot-limit and no-limit games, and this alone makes them worthy of consideration as a big-bet option.

Half-pot, like limit-betting, is a game which provides reasonable odds for a call -- 3/1 in a head to head contest, as opposed to 2/1 in pot-limit -- and as a result there is more action and multi-way pots than in pot-limit and no-limit. Because half-pot is a big-bet game, bets and bluffs do not decrease in effect as the hand progresses, as they do in limit, where a final round bet can be as little as two or three percent of the pot. In effect, half-pot combines the best features of pot-limit/no-limit, and limit-betting: it has multi-way action, favorable pot-odds and reasonable bankroll longevity, like limit-betting, and it's also an excellent bluffing form in which pots and bets build quickly, like PL and NL.

Here is a chart comparing half-pot and pot-limit pot sizes and bets in a 50-100 (cents or dollars, depending on your BR) game of holdem. In this example the opener raises, and then bets at every round, and one player (other than either of the blinds) calls at every round, and then raises and is called at the end. The pot size at the start of each round includes all bets and calls for the preceding round, so the pot at the start of the second round in the half-pot column is 150 (blinds) + 100 + 125 (call and raise) + 225 (call) = 600.

   Half-pot                                  Pot-limit
Start:  call 100, raise 125                       call 100, raise 250
Flop:   pot 600, bet 300                          pot 850, bet 850
Turn:   pot 1200, bet 600                         pot 2550, bet 2550 
River:  pot 2400, bet 1200                        pot 7650, bet 7650
        raise 2400, final pot 9600                raise 22,950, final pot 68,850

The rapid escalation of the bets means that a hand of PL in which there is serious action at every round of play is something of a rarity, because players with average bankrolls tap out after three or four bets. Four rounds of action, even multi-way action, is common in half-pot play.

Pot-limit is good, but half-pot lasts longer.

While it is perfectly understandable that some players will always prefer pot-limit to half-pot -- and if bankroll conditions and the players are right I like it myself -- I believe it is a mistake to dismiss half-pot as a big-bet game. A half-pot game can survive for years in a situation where a pot-limit game would quickly break many of the available players and revert to limit-betting. The situation in the USA and Canada -- where pot-limit games can be hard to find -- is a reflection of this tendency of limit games to push out pot-limit. Players who prefer big-bet poker but who spend most of their time playing limit because the pot-limit game folded again, (or because their own bankroll can't handle the big swings) might consider half-pot betting as an alternative, if not to pot-limit, at least to limit-betting.