Unfortunately there are two different types of passive players. The first of which will be the main focus and is defined as a player who bets small with top pair, straights, flushes, etc. This first type of Passive Player is a losing poker player by definition and is setting their bank account up for huge losses due to their inability to protect their, at the time, winning hand. The second is the slow player. The Slow player pretends to be a passive player allowing others to do the betting for them when secretly they hold a monster hand and are just waiting until there is enough money in the pot (or a possible draw to destroy their nut hand) appears on the board and the slow play routine has to end in order to protect the hand. Some slow players never pick up on this and will allow their great hand to turn to garbage by simply not betting enough to protect it. Passive Players suffer from the same problem. Passive Players / Slow players are trying to allow other players to believe they are in control of the hand when actuality they are not. This is a great system to use when your hand can’t be beaten / outdrawn but most be dropped the second your hand is in danger of losing. Thankfully a good percentage of Passive Players and Slow players have never learned this lesson and will allow you to take pots that should have been rightfully theirs and instead win the pot on the turn or river with a better hand.
Step one is to identify whether or not the Passive Player / Slow player will indeed protect their hand when necessary or allow you a look at free / cheap cards. If they protect their hands then leave them alone until you hold a hand that can’t be beaten then bet normally. This works exceptionally well against opponents who flop straights / flushes / three of a kind / two pair /etc that just so happen to be a little weaker than your hand. Let’s say you flop an ace high flush while your slow playing opponent flops a king high flush. You’ll bet out like normal and your opponent will believe they are in fact trapping you when you have set a reverse trap. Your normal bet shouldn’t set off any alarms in the head of the Slow player / Passive Player that you in fact hold the nut flush but rather show that you hit top pair or something similar and are simply testing the waters to see if anyone has hit a better hand. You are both slow playing other opponents as well as the slow player at the exact same time with the feeler bet. Slow players, unlike Passive Players, will at some point become aggressive and try to bet you out of the pot, thinking they hold the nuts, when in actuality you have been holding the nuts the whole time and have been using their system to beat them.
As for the common Passive Player they will bet small whenever they hit top pair, two pair, etc giving you cheap pot odds to draw toward your straight / flush / trips / boat /etc. You will want to pick up on what sort of starting hands the Passive Player typically plays to give you at least a general idea of what they hit on the flop before making a lot of cheap calls in an attempt to outdraw them when there was in fact no possible way to outdraw them. Normally that won’t happen however, and the Passive Player will allow you to reraise pots with basically nothing (if you smell weakness) and swipe the pot away from them. The Passive Player has a terrible time of protecting winning hands and will wind up making terrible calls on the river after you have indeed outdrawn them. Use pot odds as your tool of whether or not to attempt to outdraw the Passive Player. Typically if you have a 4 out straight draw its best to fold or reraise the Passive Player in an attempt to pick up the pot right then and there. This will also give you information as to how committed the Passive Player is to their hand and after a few reraises you should have a general understanding as to what to expect while playing against a specific Passive Player.
The best thing to do is if you feel beat / don’t have a worthwhile draw against your Passive Player / Slow player opponent is fold. By folding you are giving them much smaller pots than they would have received had you called along and lost the pot. Let the blinds do their jobs and slowly take every last chip from the Passive Player until they’re broke. As with the Tight Players target any opponents that seem to feed the Passive Players / Slow players unnecessary chips as they, just like their Tight Playing counterparts, will be harder to win chips from if they do somehow become the chip leader due to their small betting nature and ability to fold to raises even when they do in fact hold the best hand.
Summary. Pay attention to what sort of hands your Passive Player / Slow player opponent tends to play to give you a more narrowed idea as to what hand they’ve hit when they bet small. Use Pot Odds or Investment Odds as guidelines on calling / folding to the small bets made by a Passive Player. Mentally label whether or not your Passive Player / Slow player opponent protects their hands against draws or simply sticks to a basic system of betting small allowing opponents the chance to outdraw. Use raises to test the commitment a Passive Player (not a Slow player, who will instantly reraise you) has to their hand as well as their ability to judge who holds the winning hand / their read on you. Stay out of pots where the odds / outs are not in your favor when it comes to Passive Players / Slow players. The blinds will slowly eat them away as they will not receive the amount of chips their winning hands should have typically won. Attack opponents who feed the Passive Players / Slow players chips because a Passive Player with a lot of chips will be harder to defeat than a Passive Player with few chips.