[Aaron W.]

What does "protecting your hand" mean to you? The last paragraph of page 153:

To "protect your hand," you must bet or raise. Your bet should force players who hold weak draws to decide between folding and making an unprofitable call.

On the flop, the pot is 12 SB. Two overcards have as many as six outs, giving them about 7:1 to call. Sadly, you don't force those six out hands to make that decision. However, it's possible that the one of the overcards is an ace, which means that you have them reverse dominated and now their 3-outs aren't getting good odds (3 outs = 15:1).

It's also possible that some of the overcard hands will fold even though they do have odds. For example, QJ isn't so thrilled with his hand and may give up here (he doesn't know his outs are clean).

How much is it worth folding just one set of overcards? It's an extra 6 cards that can fall on the turn that are safe (6/45 = 13%). That means an extra 13% of the time, you'll still be ahead on the turn when you bet the flop. That's not bad, and it's reasonably likely that you'll get two players to fold.

(Consider also that even if you get 4 out of 5 callers, they are padding the pot with even more money for you for those extra 13% of turn cards.)

You have got to bet your top pair in this position every time. (But you should have folded preflop and never found yourself in this position in the first place.)