>>212398573The two of them are fighting dismounted with no allies? Jaimie, particularly if he has armor. Dothraki consistently do poorly against opponents with westerosi armor in single combat. Drogo is a tough dude, but not a ludicrously skilled warrior like Jaimie.
If it's a fight between warbands or armies, Jamie loses hard. He was only ever a middling field commander, while Drogo was an incredibly successful warlord.
If they're fighting a mounted duel, it's a draw. Drogo could probably do a lot of hit and run maneuvers that Jamie can't match despite being a good horseman himself, but Jamie's armor and weapons still even things out given Dothraki mostly fight with long sabers rather than lances.