In the pairs event played on consecutive days across the county's three Ryder Cup venues – Moortown, Ganton and Lindrick – they lead by just one from Bedale's Tim Morris and Martin Fuller, who also opened at the 1957 Ryder Cup course.
Top score at Ganton was a hugely impressive 45pts, carded by Brampton Park's Jody Greenall and Richard Scott, while two pairs shared the honours at Moortown with 44pts – Rockliffe Hall's Gary Varley and Lee Bennett plus Paul Burnley and John Billany, from Beverley & East Riding.
MacCafferty and North produced six birdies between them on their opening seven holes, including a two at the 140-yard sixth from the latter, and had 24pts to their name by the turn.
They began the back nine with their only one-pointer of the day before making huge amends with net birdies at 12, 13 and 15, a gross two from MacCafferty at the difficult 210-yard closing par-3 and a birdie for net eagle from North on the 487-yard par-5 16th.
Morris and Fuller had four birdies on the way out including three on the spin from the fifth.
They had four more on the homeward run plus a birdie for net eagle from eight-handicapper Morris at the 394-yard par-4 17th.
Burnley and Billany began at Moortown with five successive birdies and added a sixth at hole seven on their way to an outward tally of 24pts.
They had three birdies in their first four back-nine holes and would have led the Moortown Division on their own after day one were it not for a blob at the last.
Varley and Bennett opened with a marginally more modest three consecutive birdies and put 44pts on the board despite three one-point holes.
Ganton Division leaders Greenall and Scott had five birdies on the way out and six on the trip back to the clubhouse, four of those half a dozen coming in the first five back-nine holes.
Reigning champions James Appleyard and Miles Foster, from Howley Hall, opened the defence of their title with a solid 41pts at Moortown.
Two-handicapper Appleyard picked up five birdies and shot three under despite lipping out for birdies on four occasions with his birdie at the 13th, a shot hole for him, contributing their one four-pointer of the day. Bogeys for each at holes two and 11 meant one-pointers and a rare example of them not dovetailing, which they did so superbly last year on their way to the championship.
Yorkshire Post competition winner Bryan Schofield (Cleckheaton) and his playing partner Nigel Clough, of Hanging Heaton, carded 41pts at Lindrick to place inside the top 10 for the day.
Highlight of their score was a birdie four for net eagle at the 478-yard par-5 fourth from 14-handicapper Schofield despite him having found a fairway bunker with his drive.