Phony Benoni: The reference is to "Mr. P.R.O.P", a character in a story related by Al Horowitz in Fred Reinfeld int heir book, "Chess Traps, Pitfalls, and Swindles."
This occurred in the days when Horowitz was making a living playing NNs for small stakes, often giving large odds. Mr. P.R.O.P. was a "Professional Rook Odds Player".
One day, Mr. P.R.O.P. came to the club with a proposition for Horowitz. "I'd like to play a game at the usual odds for a stake will be $10. At times during the game, I may suggest you take back a move and play a different one. If you accept my suggestion, I'll give you dollar. If you refuse, it costs you nothing."
This sounded odd to Horowitz, but what did he have to lose? He accepted the challenge, removed his rook from a1, and the game began.
<1.d4 Nf6> 2.Nf3
Mr. P.R.O.P said, "You know, the great Capablanca former champion of the world, used to play 2.Nd2 here, and I've been studying the move. If you take back your move and play 2.Nd2 instead, I'll give you dollar."
Horowitz thought this was an odd move, but, hey, if the great Capablanca played it, how bad can it be? So he pocketed a dollar, and the game continued.
This startled Horowitz. P.R.O.Ps <never> sacrifice material. Still he was about to take when it hit him -- "He wants we to take the pawn! If I play a different move, he'll offer me another dollar to take the pawn!"
"It you take the pawn instead, I'll give you another dollar!"
"Ha ha!", thought Horowitz. I've got the hand of this now!"
<3.dxe5 Ng4> 4.Nf3
"If you take that back and play 4.h3 instead, "ill give ou another dollar!"
Now Horowitz was a bit suspicious, but he quickly realized what was happening. Mr. P.R.O.P. was nervous about giving the pawn away, and wanted to be sure he got it back. So he accepted:
Now the truth became known, as everyone in the club collapsed in laughter.
Mr. P.R.O.P. thought of offering Horowitz a dollar to take the knight, caught a glance at the look on his face, and decided that particular game was over.
And Horowitz, having started a rook down, has managed to lose his queen for a knight in the first five moves.
There is a moral to this story. Or, at least, there should be. You see, despite everything, Horowitz wound up winning the game anyway!