Casinos don’t like it when you are the only player at the blackjack table. Part of the casino’s advantage is derived from the dealer playing against several customers at the same time. Whether you count cards or not, you will see less volatility in the distribution of the cards if you are the only player facing the dealer.
The pit boss may close other tables or send over some house players to fill up your table if you get a lucky break and can play the dealer by yourself. Don’t get upset when this happens.
Why does it matter how many players are at the table? Because your chances of getting those high value cards decline as more people draw from the shoe. When it’s just you and the dealer you have an even chance of drawing the cards you need. As more people join the table your chances drop radically.
The dealer doesn’t need to draw high value cards as often as the individual players do. That is because the dealer wins every time a player busts. Hence, if you play a conservative game in a one on one situation with a dealer you have a pretty good setup. But the house advantage will never fully vanish. Sometimes all you are going to get for a third card is a bust card and there is nothing you can do about that.