The style of bareknuckle fighting was much different than today's boxing. The jab was pretty much nonexistant. Fighters like Sullivan were noted for rushing forward and pummeling their opponent. Wrestling holds were allowed above the waist and were used in later rounds because many of the fighters damaged their hands early on in the fight. I wouldn't count these guys out though, read about some of the fights which involved strangling, knee drops to downed opponents and spiking opponents legs. "Gentleman" John Jackson beat Mendoza by grabbing his hair and beating him senseless. This stuff makes head butts and low blows look fairly tame.