SANTA CLARA >> The 49ers are at their best as front-runners. Get a lead, then dictate the pace while gradually squeezing the life out of their opponent like a boa constrictor. They’ve been that way for a few years now, but have taken it to an extreme this season.

Last Sunday, for instance, it took just two series — one on each side of the ball — for the 49ers to announce their return from a three-game losing streak. After the defense had forced a three-and-out on Jacksonville’s first series, the 49ers’ offense went 57 yards in four plays for a touchdown.

It marked the sixth time in nine games that the 49ers have scored a touchdown on their first possession. Throw in a first-drive field goal against the New York Giants, and the 49ers have scored 45 points on their first drive while giving up just 13.

To 49ers coach Kyle Shanahan, it doesn’t much matter when you score but that you score.“You want to start out great and do it on the first as much as possible,” he said, “but I’ve never made a big emphasis to our team about that being more important than any other one.”

In first drives over nine games, quarterback Brock Purdy is 26 of 31 for 295 yards, four touchdowns and no interceptions. Three of those five incompletions came in succession against the Giants in Week 3 when the 49ers had to settle for a field goal on the their first possession.

When informed last week that he had just two incompletions on opening drives other than against the Giants and a 145.9 passer rating (158.3 is perfect), Purdy paused for a moment in front of his locker.

“Wow. That’s crazy,” he said. “I didn’t know that. We just go out and execute the plays. I had no idea.”

Christian McCaffrey’s first-possession stats are eye-popping — 26 carries for 161 yards and two touchdowns plus five receptions for 51 yards and another TD. He credits Shanahan.

“Obviously, Kyle’s really good at calling plays,” McCaffrey said. “Has been for a long time. For us, each play has a life of its own. That’s the way I look at it. You can’t really predict a whole lot in this league and you’ve just got to trust the play-caller — who’s really good at what he does. You can’t mess up.”

The 49ers started this trend in Week 1 at Pittsburgh, following up a defensive three-and-out with a 54-yard touchdown drive. Their two other most convincing wins of the season, 40-12 against Dallas and a 34-3 win over Jacksonville, began with opening-drive touchdowns and a defensive stop.

Opponents know what they’re in for if the 49ers get rolling early.

“We did all the stuff we talked about not doing during the week,” Jacksonville quarterback Trevor Lawrence said postgame Sunday. “We start with a three-and-out, gave them momentum, and they went and scored. That’s just not how you want to start a game against a team like this. They’re really good, especially playing with a lead.”

The six opening-drive touchdowns match last season’s total over 20 games (including playoffs). Adding field goals, the 49ers outscored their opponents 53-48 last season on opening possessions. In 2021, over 19 games, they had five touchdowns and a 41-30 margin. The high-water mark under Shanahan came in 2019 when they scored seven first-drive touchdowns, held a 64-34 margin and went to the Super Bowl.

Being at six first-drive touchdowns and 45-13 margin through nine games is pretty heady stuff.

“Obviously, you want to set the tone for the game, but at the same time, it’s usually plays we’ve run in practice and we know those plays a little better than ones we hadn’t run multiple times,” center Jake Brendel said.

Without knowing firsthand, Brendel suggested negative runs, sacks and penalties were virtually non-existent on the first possession.

“We probably never went backwards, and that just comes down to being dialed in, knowing the snap count and having the operation at 100%,” Brendel said.

Sure enough, the 49ers haven’t had a penalty on offense in any of their first drives and just one 4-yard sack of Purdy in Week 3 when they settled for a field goal.

Defensively, the 49ers have opened three-and-outs four times, had two interceptions, given up two field goals and one touchdown.

While linebacker Fred Warner is all for getting off to a good start, he stressed the 49ers need to win in other ways as well.

“I’m sure it’s something other teams talk about because they know if we get going hot from the start that it’s going to be hard to stop us once we get rolling,” Warner said. “I want to see who we are when we don’t get the stop on the first drive. It’s all about finding a way to win. We’ve got to make sure we’re on it, not only from the start, but especially the finish.”