You have many tasks as a poker player but making correct decisions is the primary one. A correct decision in poker isn’t just about checking with the probable worst hand or folding but also knowing when to profitably bluff with the worst hand, knowing when to check with the best hand and so on. Generalisations really hurt you in poker and checking and folding with the probable worst hand is one such generalisation.
Let us say that you raise pre-flop with 100bb stacks and you have 8-8. The big blind calls you and we see a flop of 6-6-2 and you c-bet after they check. They call and the turn goes check-check. The river is the Jh making a final board of 6-6-2-3-J. They bet nearly the size of the pot on the river and now you have to decide what to do. Cleary their bet potentially polarises their range and so your eights could be good.
Likewise if you value bet the river and get raised after your opponent took no aggressive action earlier in the hand, this play against certain opponents has the potential to be a bluff. So extracting value in poker isn’t just about betting good hands but knowing when to call bluffs with marginal hands and also when to check the likely best hands also. It will not be possible most of the time to bet and expect to get called by weaker hands on all three streets and so to extract the full value possible means checking as well.
