Your chances of success are slightly lower if you submit on the deadline

What are you waiting for?  The next NIH Parent R01 deadline is Wednesday, October 5th.  If your proposal is mostly ready and you are making final adjustments, stop procrastinating and get it finished, already!  If you are not even close to finished and won't be able to submit until close to 5:00 p.m. on Wednesday, perhaps you should defer to the February 5th deadline.  Read this excellent post for the reasons why.