>>28604488The standard Machamp does 56.8% to the standard Conkeldurr with Dynamic Punch, whereas Conkeldurr does 46.9-55.4% with drain punch, meaning he recovers enough HP with drain punch to not die to a second Dynamic Punch.
Assuming Conkeldurr does not ever get confused in the two turns, it has a 74.2% chance of winning.
Factoring in confusion, which says there is a 23.4% chance to not ever hit yourself, Conkeldurr has a 17.4% chance to win.
So you are right but it depends on luck.