Answer:
The British soldiers, also known as "Redcoats", did not fight effectively as the American colonials because of their motivation. Enlistees from England only joined the military for the money, which was not much. The average Redcoat was paid about 8 pence a day, according to NPS.gov. This decreased their willingness to fight, but not as much as the next reason.
The Redcoats were forced to fight whether they felt like it or not. The colonials, however, had the drive to push the British out of their land, because of the actions the British government had imposed.
Many of the battles in the American Revolution were actually British victories. Nevertheless, the motivation of the colonists never extinguished, giving them the edge over the Redcoats that would eventually lead to their victory.