This is, for me, the one & only determinant as to whether or not a 'contact play' worked. I HATE the 'contact play'. It's bad strategy. Trust a professional baseball player to use his instincts and judgment, & read the ball off the bat to determine whether or not he tries to score on a groundball in the infield. Imo the 'contact play' is the equivalent of telling a runner on 3B to attempt to tag up & score on any flyball, no matter how deep or shallow it is, and without considering if the OF throwing the ball has an arm like Khris Davis or like Carlos Gomez. Runner's should try to tag from 3rd on every flyball (to an outfielder) just to draw a throw and then go back if you will be clearly out. It can allow other runners to advance or lead to a bad throw that you could score on. The difference is that you have the time to get back to the base because the ball is in the air. On the infield grounder contact play you cannot start running, notice the ball was a 2 hopper to the SS, and then go back to 3rd because you will be too far off. So really what you have to do it wait until the ball gets through, but then you lose the chance to score on balls that require the infielder to dive, or when they make a bad throw. The contact play allows you to score a run when no other play would allow you to score a run, so it is not a bad strategy. The question is if it is worth it in terms of the net WPA before and after, and I'm not sure how to get that data. It's also not that rare on these plays when no out occurs because the infielder throws home late and does not take the out at first. Of course the contact play does not override the "freeze on a liner" rule because in that scenario you can wait for the ball to get through and score easily. Infact, with the contact play on you should start running back to the base on a liner as soon as possible instead of freeze