Cromwell’s cavalry formed up on a hill and the royalists did the same on another hill very close by, with a ‘little place’ or ‘plain’ between them. The parliamentarians were expecting a royalist force to attempt a relief of the siege of Bolingbroke and they are thus certain to have reconnoitred the whole area and considered the options for fighting such a force. It is therefore likely that this ground at Winceby had already been chosen. That it was a careful choice is made clear by the official royalist report, which states that the parliamentarians were deployed in a place where the frontage was constrained such that only three divisions of horse could charge at any one time.

Constrained by the narrow ground which Cromwell had chosen, the cavalry formed up in three divisions with a further three divisions in reserve. The dragoons on both sides formed a forlorn hope in front of the cavalry deployment. On the parliament side the forlorn consisted of 5 troops of dragoons under Vermuyden. In the parliamentarian battle array the vanguard was commanded by Cromwell, but the Earl of Manchester’s regiment, because it was the senior regiment, had the right wing. Cromwell’s, under his personal command, had the left wing. Fairfax had command of the three reserve divisions and his regiments, as the senior in the reserve, had the right wing.  The royalist horse also deployed in three divisions. Saville had the command of the right two divisions of the vanguard while Ethyn together with Henderson, presumably with his Newark Horse, combined to form the left division, which comprised eight troops. There were then further divisions in reserve.

Vermuyden's forlorn hope will have consisted of up to 300 - 500 men, as a normal dragoon regiment comprised companies of 100 men while cavalry troops conmprised 60, when at full strength. The frontage for 8 troops, if up to strength, would be 60 men, giving in all 480 horse, though the troops of horse of the royalist forces do seem to have been under strength. If each division was of the same strength then the vanguard would have comprised some 1400 men. If Cromwell had 3000 cavalry and dragoons, leaving out the 300 under Vermuyden’s command, would leave 2700. Assuming Cromwell and Fairfax had equal numbers in the vanguard and the reserve this gives about 1350 each, divided into three divisions giving up to 450 per division. Accurate calculations as to the ground taken up by these forces can be made from the contemporary military manuals (Ward, 1639). The normal deployment for cavalry was 6 deep with a spacing of the frontage of 5ft per horse. This gives a frontage of 375ft per division and allowing 20ft spacing between divisions makes in all about 1165ft for the whole frontage. The depth for each horse was 10ft and thus at 6 deep 60 ft depth for each division. The distance between van and rearguards is 100ft. However, before engaging the cavalry would presumably double their files to close order, giving a line three deep and enabling the riders in each line to lock knees, as Vernon (1644, fig 19) describes, so that the divisions of horse closed as a single body, enabling them to better retain cohesion as they engaged the enemy. They would then charge at a ‘good round trot’ only breaking into a full gallop in the last few strides.