The black, green and gold finished fifth in the Gallagher Premiership for 2020/21, bowing out of the Champions Cup at the pool stages and the Challenge Cup at the quarter-final barrier.
Boyd has so far overseen finishes of fourth, eighth and fifth since moving to Saints from the Hurricanes in 2018.
And he said: "The 18/19 season, which was my first one here, we snuck into the top four and everyone thought we had a pretty decent year but we'd won 11 and lost 11 and got into the top four with 56 points.
"This year, we won 11 and lost 11, and we scored 57 points.
"That much-vaunted top four, which we were chasing at one point, finished that far ahead of us that we were probably out of the top four at about Christmas time.
"So there's some pretty harsh lessons in there around the need for consistency.
"The one thing we were very consistent about this year was being inconsistent.
"There's a number of reasons for it: we changed our approach to the game and put a different emphasis on what we thought was important. We went more conservative and back to basics.
"Sometimes it worked and sometimes it didn't.
"We were never able to pick our best side from round one to round 22.
"The column that I've got on my spreadsheet that says 'not available for selection' always had people in it that you would have selected if you could have, and often there were up to 10.
"We've still got some growing and developing to do in key areas, in our number twos and number threes in those positions.
"We started to rely on people who were less experienced and didn't have as many runs on the board.
"There are multiple reasons.
"In terms of the losses, we could point at one part of the game one day, another part of the game another day and another part of the game another day.
"We look back and rue some losses, like losing to Bristol and Bath twice, both at the death.
"We were in one-point games 11 times, and we won six of them and lost five of them.
"There wasn't anything you can really put your finger on, there was just something half the time that wasn't good enough to get the win we wanted.
"It is frustrating but at least you know you can fix it.
"The basics of our defensive game have improved significantly in the past 12 months.
"We've talked about it in debriefs that we've got to set higher standards that we're not prepared to dip under."