You're very best is all you can do...I'm sure you're gonna do great! Not sure what specifcs you're looking for on the sweepers, maybe I can help. Sweepers will start after the very last runner crosses the start line and from there will maintain the 16 min per mile minimum pace. This means that the further you start ahead of the last person, the more of a cushion you have built in. I've read that there are certain sweeping spots and at those places there is a bus waiting and race officials will block the course at those points when the sweeper passes and anyone behind will unfortunately not be allowed to continue. I have also heard that the sweepers will sometimes give some verbal warnings...letting everyone around them know they are there and they need to pick it up a bit and stay in front of them. They are sometimes also called the "balloon lady"...I'm assuming because he/she wears baloons on them somewhere? However, don't confuse them with pacers...you may see some runners in the corrals or throughout the race course holding a stick with balloons on it and a time written on the balloon...like 2:45 or 3:00, etc...that's a pacer who you can stick with throughout the race if the time on their baloon is your goal time and they'll get you across the finish line in that time or less. So not all balloons indicate a sweeper! I believe that anyone picked up is bussed to the finish area and is still offered a medal. Try not to worry about it though...just run it the way you trained and have fun

If you're concerned with being too slow and happen to be placed in the last corral, get there early enough and work your way up to the front of your corral...this will give you at least a few minutes cushion. Good Luck!