Strategy? My strategy would be to forget that HISTK playground existed! Steer the kids far away from it. LOL Like the OP, we have ds4 and dd2. We each took responsibility for one child. At one point we were all together, both kids went down the slide tubes. DH ran to the bottom and I slid down right behind ds4. Would you believe we lost him? He took off so quickly that we both missed him. It took a minute or two to find him - he had run right back up to slide again. But that was the end of our adventure, we were OUTTA THERE!