[bob jenkins]

Originally Posted by mbyron

I don't see how you prevent a DP here. The runners will either tag up or not.

1. If the runners tag up, they can leave after the fielder first touches the ball. No second out is possible whether or not he catches it.

2. If the runners don't tag up, then they're going halfway or returning to the base. If the fielder juggles the ball, he'll end by catching it or dropping it.

(a) If he catches it, the BR is out and the other runner goes back to his base;
(b) if he drops it, the BR will be on first and the other runner liable to be forced out. Either way, no second out is possible.

There's more than one forced runner in the play being discussed. These runners (and not the BR) are the ones who would be involved in any DP.