Why is the expected return sometimes greater with more players in single deck?

[bjoe]

I intuitively guessed that playing a single deck game was generally more profitable when 1 on 1 with the dealer, than at a full table where you might get 2 hands before a shuffle. This is assuming that the decisions made for the hand incorporate all the visible cards from the current deal (is that a safe assumption for the sim?). I ran a sample set of sims for 1 through 7 players using hi opt 1 with 6-5 payout and qtr deck resolution and got surprising results. Am I reading the results incorrectly, and is there an intuitive explanation for why the returns are not progressively better or worse as you go from many to one player?

Ranked by worst to best DI, I get:

4P : 2.18
2P : 2.90
5P : 3.36
1P : 3.65
3P : 3.86
7P : 4.17
6P : 4.40

_Custom Hi Opt 1 6-5 Pay : Qtr deck TC : 1P.jpg_Custom Hi Opt 1 6-5 Pay : Qtr deck TC : 2P.jpg_Custom Hi Opt 1 6-5 Pay : Qtr deck TC : 3P.jpg_Custom Hi Opt 1 6-5 Pay : Qtr deck TC : 4P.jpg_Custom Hi Opt 1 6-5 Pay : Qtr deck TC : 5P.jpg