The only way to win every hand possible is to play every hand and call all bets or raise. You win a lot of hands, but you will lose a lot of money. Many players feel it is cute to win with hands like 7-2os, the Dolly, or the Sik. It is cute but they pay a lot of money for the privilege. Everyone knows not to play those hands. Many poker players fail to grasp that many of the hands considered "playable" can also cost us money, if we make a bad Big Decision instead of a bad Little Decision.
Here is a favorite. In the Big Blind, with three limpers, you hold Q-5os. The Flop is Q-8-2 rainbow. What do you do? With no pre-flop raise, you can assume no one holds A-A, K-K, Q-Q, A-K, A-Q. Your hand is probably the best hand right now. Take a stab and put in a bet? What do you do if you are raised? If you check and someone bets, do you call? Even though the "big" hands may not be out, there are still hands that have you dominated; K-Q, Q-J, Q-T, 8-8, 2-2. Those hands are all probable holdings for limpers. In fact the only hands you really beat are the other pocket pairs; small suited connectors and any Ace with the exception of A-K, and A-Q. Let's look at the options.
1. Bet and fold to a raise. Any bet less than half the pot would be suspect and most skilled players would raise, forcing the fold. You have tripled your investment in the pot, and gave up.
2. Bet and Call a raise. They didn't bluff you but you now have five times your original investment and will probably have to call at least one more bet.
3. Check and Fold. You have invested no more money and your real loss is zero, since you were the big blind.
4. Check and Call. With a half pot sized bet, the numbers probably warrant a call, but to call a pot sized bet you should have a significant read on your opponents. You have again tripled your investment.
5. Check and Raise. Well now you have five or six times your initial investment in the hand, with cards that are questionable at least, but if the bettor comes over the top you know your top pair bad kicker is a loser.
Which one of these options you select could change drastically if the game has some odd characteristics, but although numbers 1 or 3 are often the wrong decision, they are the cheapest decisions. Option 1 does give you a chance to win the pot, but it risks some extra money. All of the others not only put additional money at risk with what is a very marginal hand, they will also force you to make harder, more costly decisions on the turn and river. Your right little decision early could cost you dearly if you make the wrong big decision later.
So, what's the right answer? Well it depends upon the situation of course. Do you have a good read on your opponents? Do they have a good read on you? Is it an action game, or is it table of tight players? The real key is to make your wrong decision early when there is little at risk. You don't want to make all of the decisions correctly except the last one. The last one, after all, is the most important.