Ad aspera

The warrior greeted the count with a bow.
"Ready, ready. I'll assess you – as a solid fighter, of course! I used to serve in the guard. I participated in capturing a bandit gang. And I subdued all sorts of maniacs on the streets. So, I have combat experience."
He delicately omitted the details that for most of the time he simply stood like a statue at his post or patrolled around. And "maniacs" were usually just ordinary drunken brawlers. Although it was not difficult to guess this anyway. Perhaps his experience wasn't quite relevant to the knightly duels taking place here, but he had no doubt about his abilities.

-- Truly solid? Then your first opponent will be...
The Count looks over the assembled fighters, but before he can name anyone, one of the knights interrupts.
-- Count, I still have doubts about your idea...
-- Señor Roberto, if you are so afraid of being beaten up by a commoner, -- the Count emphasizes this colloquial word, -- you can say it directly. As I see, some knights here may share such concerns. Fortunately, even our squires seem ready for any opponent. Jean! Show what you can do. Ruven, spear.
Armed with a blunted spear, Ruven steps onto the fenced arena and begins the first fight. The opponent silently greets him, saluting with his sword raised.
There are 6 cells between opponents. The field is square, 18x18, i.e., straight back – 6 cells, straight sideways – 9.

First round.
Jean covers 4 units of distance.
Preemptive strike: hit, interrupt – failure, Jean receives (246-63)-23% = 141 damage [434/575]
Jean covers 2 units of distance and attacks Ruven.
Ruven receives (186-75)-38% = 69 damage [461/530]
Ruven receives (187-75)38%= 70 damage [391/530]
Miss.
Shield bash. Ruven receives (30-75)-38% = 2 damage. Paralysis – failure. [389/500]
 
Ruven's turn.

Notes:
I forgot about the heavy unit dodge penalty and adjusted the stats accordingly.
Damage does not drop below 5% of initial value.
If Ruven retreats, he will receive a free attack, but on his next turn, he will have a chance for a preemptive strike. Retreating one or two cells will not prevent him from attacking.
Attachment 66539