That's such an arbitrary situation that it's impossible to answer.
Is the BJJ guy Marcelo Garcia, or just some random BJJ blue belt who's only been training a couple of years? Has the BJJ guy trained his striking skills, or at least defending against fully committed striking while on the feet, from the clinch and on the ground? Or has he just been doing pure submission grappling? Has he ever trained his skills in realistic environments, or has it all just been on the mat in the dojo?
How does the fight initiate? What range does it initiate from? Is there any verbal dialogue/warning prior to the first physical attack, or is it an ambush? What type of terrain are they on/environment are they in? What is the first attack (is it a sucker punch, a grab and punch, a tackle, a grab so that his buddy who the BJJ guy didn't see can rough him up while he's temporarily immobilized)? Is this mutually agreed upon combat, your typical posturing to try to intimidate shoving match which eventually turns into a fight, or a criminal assault (mugging/robbery, gang beating, etc...)?
Is the 230 lb guy trained at all? Does he have any athletic experience (played football in high school/college, wrestled, or any other sport where he might be used to heavy contact and physicality) or generally athletically gifted (strong, fast, explosive, good sense of balance)? How old are they each? Are there any weapons involved? How about friends waiting to jump in should things start to go wrong for their friend?
And the list goes on.....