His conduct, and his conduct alone, converted the battle of the Boyne, which was in effect a kind of drawn battle, into a great victory for William.
It had, indeed, more than answered the object which the Irish commanders proposed to themselves.

Their plan was to accustom the new and badly armed levies to stand firm against the steadiness and experience of William's veteran troops, and then to withdraw without committing themselves to a decisive combat, with a view of protracting the campaign until William should be forced to leave Ireland, and his foreign army should be worn out by winter service in an uncongenial climate.

Every day would, they calculated, improve their own army and weaken and reduce that of the enemy.
Their position at the Boyne enabled them to try their plan of partial combat to what extent they chose, without danger of being forced into a more extensive action than they deemed expedient.

The Irish troops had greatly surpassed the expectation of their own officers, and had filled William's generals with amazement; and it is probable that, if a large part of the infantry and artillery had not been sent off early in the day, the experiment might have been turned into a brilliant victory.

As it was, William was so surprised and alarmed at the resistance he had encountered, that he remained some days at the Boyne without advancing.
He had been told by all, except the Duke of Schomberg, that the resistance of the Irish would be contemptible, and the most forward of those who had scoffed at the courage of the Irish had been the Enniskilleners, who had themselves, on the day of battle, shown so unmistakably the white feather.