Mark was ready to play ANYONE then! No one was barred! The only players who may have had a chance of beating him at his peak were Busti and Buddy, the two big B's.
I'm editing this to include Johnny back then. I really shouldn't have left him out. He was at his top speed when Mark was peaking. Dennis was certainly one of the rising stars in Pool at the same time, but I don't think he would have wanted to play Mark back then. Just like he would have avoided the other three on here.
It's hard to gauge their relative speeds, but Dennis was right there in the elite circle of players from an early age on. Buddy, Busti and Johnny were a little more seasoned as high stakes gamblers, and perhaps more consistent as well. They would have been my picks if they were to match up with Dennis in the early 90's. And Mark was almost in another world, his game got so strong so quick. EVERYONE was a little wary of him! And he was fearless. No doubt he would have played any of these guys, even woofing at them on occasion. Only around Buddy did I see him dummy up. He had a lot of respect for the old man.
And by the way, Parica was still THE MAN! NO ONE challenged him back then! Not Johnny, not Busti, not even Buddy. They just said hello to each other and went on their way. As good as Mark was, he would give Parica a wide berth.