Seven players are in for a flop of 8 M 7V 4 *. This is a very good flop for our hero. The main feature is a flush draw against a large field. Played properly, flush draws against large fields are very big money winners, but this flop is even better. Second pair might actually be the best hand. Additionally the 9 * kicker is an over card, and there is a three-card straight. Counting the three-card straight as one out, and counting the 9A over card as three outs, this hand might already be the best hand and has as many as thirteen outs if it's not best.

That's enough to make this hand only a small underdog against one player. Against two or more players, this hand is probably worth a raise. Against three players this hand is certainly worth a raise if you're certain that three of them will call. Of course it would be nice to have everyone fold and win the pot right now, but as that isn't likely to happen, you'd like to have as many callers as you can get so that you get maximum odds on your draw.

The first three players checked. There was a bet. The next player raised. The sixth player called, and our hero called. Then the pre-flop raiser, who had initially checked, reraised; the other two players who had checked folded; and everyone else called.

Let's look at this in two stages. First the initial call on the flop by our hero. An argument can be made for not raising initially on the flop because there were still three players who hadn't had a chance to call, and he didn't want to discourage them from calling. With three players who will almost certainly call a reraise, a raise would not be wrong, but it's a situation calling for table judgment. If you have reason to think that a couple of the the players who had initially checked will call for two bets when they wouldn't call for three bets, then just calling and going for the overcalls is the right thing to do. If, however, you think that an extra bet won't affect whether any of those three players will call, you should go ahead and raise.

You should also check, intending to back-raise, if you think that one of the early position players was planning a check-raise.
In any event, our hero called the first round, and the situation was such that it's not really possible to be sure that calling isn't better than raising here. After the big blind check-raised, however, our hero should put in the last raise when the betting gets back around to him. He's last, and there is no one else behind him who might raise; everyone has already called a bet and two raises, so they'll call another raise. With a flush draw and many callers, you want as many players calling as many bets as possible. With the extra features of this flush draw, that becomes even more important.

In the Internet discussion, our hero explained why he didn't raise. It was because he was concerned that someone might be drawing to a bigger flush than his 9-high. That's a common concern among players who habitually take a made-hand-versus-ad raw perspective to Hold 'Em. It's also a common concern among Hold 'Em players who play a lot of seven-card stud.

In seven-card stud, if you have a flush draw then the chances that someone else also has a flush draw are higher than they would be if you didn't have a flush draw. Their draws are likely to be in a different suit than yours. The reason is that if you have four Spades, then the remainder of the deck has a higher proportion of Hearts, Diamonds, and Clubs than it normally would. If you have four Spades, then the chance of someone else having four Hearts is larger than it would be if you had one card of each suit. So, in games such as seven-card stud that don't have shared cards, you should be very careful in drawing to flushes that aren't headed by an Ace. A 9-high flush can often be beaten by a larger flush.