Question about blockers/unblocking

If you have a card of the flush suite(that is you have a flush draw on the turn)- you are unblocking villains folding combos.

Of course, you also have higher equity with your flush draws. So FDs are more likely to bet turn than non FD combos BUT it isn't that simple. If you bet all FDs on the turn you will likely be bluffing too much and on 4 flush rivers you will likely be bluffing.

Yes you want one of the flush cards in your hand to bluff turn here. It makes it less likely they have a flush, which means it blocks flushes. That's what the term blockers means. Solvers will also mean turn flush with some air ball hands on occasion (zero equity or very very little equity and no club in hand) so you can be balanced and bluff river with air when it four flushes.

This response deals with another aspect of turn flush draws and that is the concept of implied odds, which considers the chance of a flush hit on the river and winning a big pot. Implied odds may justify a turn call that is not EV profitable.

Example: Street is Turn. You and villain have stacks of about 500. You have a flush draw with a river hit probability of about 20%. Pot is 100 and villain bets 75. Assume if you hit your flush and villain calls, you will win 80% of the time on the river (e.g, villain may hit a full house).

Your turn EV with calling the turn bet assuming river checks is:

EV turn with flush draw = 0.20*0.80 *(100 + 150) - 75 = -35.

Implied odds deals with calling the turn and betting the river only with a hit.

If villain will always call your bet, a river bet of about 290, a little more than a pot size bet, makes the turn call profitable; this is equivalent to implied odds of 6.2 to 1, less than ½ of what is usually recommended.

If villain will call your river bet 75% of the time, you need implied odds of about 7.2 to 1.

Yes you want a flush card in your hand, preferably the ace of that suit, so that even if you get called, you can improve to the nuts on another flush card, or at least you block your opponent from having the nut flush.

Even better would be to make this play with a decent pair in your hand, such that an ace on the river makes you aces up, or you might make trips, say, if you had Ad9s on a board of Td9d2c5d. You can improve to the flush, trips, or 2P, but also rep the nuts on a brick.

Even if our opponent has a flush, he won't necessarily want to put a ton of money in without the nut flush, especially on a paired board. So we can play our trips and 2P like a value hand, or a bluff catcher, or as a bluff, depending on the situation.

Flush suit is good not just because it blocks the flush, but also because it blocks the one card backdoors that will either call or bluff raise on you the turn.

Interestingly, if the flush doesn't get there on the turn, then the flush blocker (especially the nut blocker) can often be bad instead. This is because it blocks a lot of the one card backdoors that will float flop and fold turn.

Eg on 9d6d3s, Ad5x is nice to double barrel on flush completing turns. But on blank turns, it blocks lots of AdJx/AdTx that might call flop and fold turn. These combos tend to outnumber the flush draws that will call, so you usually want to give up with any Ad bluff.