I play pool with friends for small stakes socially. One day when two of us were blowing shots on the final shot or two of 9-ball a lot and painfully prolonging games, we had the idea to add this rule:

At any time in a rack, start of a turn or at any point in a turn, either player, shooter or non-shooter--can call it, as of that moment/position on the table, the last turn for double the bet. The non-calling player then has the choice of taking and playing the position, or giving it to the caller. If the player taking the last turn makes the 9, they win double. If they fail to make the 9 on (the rest of) that turn/inning (run of legal shots), they lose double. (It is not required that anyone call last turn each rack. And obviously it can only happen once per rack.)

I've heard the term "press" before from golf gambling friends. Is the above rule the same idea? Or a good seeming rule? Should the non-calling player have the right to forfeit for the original single bet?

Another relevant point is that there will often be uneven odds on the bet to even out the players. So the game might be 2-to-1, $10 vs $5. And the call of double then makes the game $20 vs $10.

Attempting to analyze a bit: If we ignore any possible effects of pressure--if the odds stay the same, then I guess the doubling effect just adds variance. (And speeds up the game, as desired.)

With obviously one important point being that in 9 ball, there aren't two sides/positions on the table, as there is generally in 8 ball, or backgammon (which also has doubling). But then you could have the rule in 8 ball and just allow switching sides if double is called.