That's in RO6 single deck games
In a rule of six single deck game, the number of players directly affects penetration. Considering an average of 2.7 cards per hand, one player getting five rounds per deck will result in an average of 27 cards per deck being dealt. Two players receiving four rounds will result in a 32.4 cards per deck average. Three players getting three rounds will see 32.4 cards per deck. Four players at two rounds see 27 cards. Five players with one round will see 16.2 cards. If you are lucky enough to get two rounds to five players, then the penetration bumps up to 32.4 cards per deck. The problem with five players is the game is very slow. The best EV per hour combination in such games is two hands.
Once you get to multiple decks, this effect is greatly diminished in terms of EV per hand. If the game is played with a shuffle card, which is the norm in multiple deck games, it is non-existent. You mentioned a cut card in pitch games. If you mean single deck games as opposed to double deck games, a cut card is problematic. There is the cut card effect, which is at its greatest in single deck games, although it also has some impact in double deck games. You will get more rounds if the big cards are coming out, which means your last round or two will be in negative counts when the house has a greater advantage. If the small cards come out early, you will get fewer rounds as the count rises. In the end, this means you will be playing more hands in negative counts than you would in a game without a cut card, and that means lower EV per hand. You will be making your small bets when the big cards are coming out, and when the small cards come out and the count rises, you will get to the cut card sooner and won't be able to make the big bets you need to get the money.
You also mentioned the fact that with more players, you will see more cards dealt after the cut card has come out. That is true, but it doesn't mean much. What is important is the penetration before the final round is dealt, because that is when you will be making your final bet for that deck or pack of cards.
Now let's get to the notion of other players "stealing" good cards in high counts. In general terms, you will be in a postive count about 30% of the time (this can vary depending on penetration and number of decks, but it is an overall rough average). That is true whether there is one player at the table or six players at the table, with the exception of single deck RO6 games as mentioned above. With fewer players, you will see more positive rounds per hour, but not more positive rounds per number of total hands dealt. What this means is that in a heads-up game, you'll tend to get those positive hands all at once, while in a game with more players, those positive hands will be spread out over several decks or shoes. It is a matter of speed, and not a difference in total numbers of positive rounds per hands dealt. The other side of the coin is that, if you are playing all hands in a heads-up game, you will also get all of the cards during the 70% of the time you are getting neutral or negative counts.
Of course, players coming in midshoe can affect this, but that will tend to average out as well in the long run.
I hope this makes sense and is clearer than mud. :-)
