EL SEGUNDO >> Darvin Ham has been through playoff series before, but it’s different when you’re in the No. 1 chair.

And in a milieu where adapting and adjusting is critical, he’s showing as a first-year head coach that he can hang with one of the masters.

The Lakers are ahead of the defending champion Golden State Warriors 2-1 going into tonight’s Game 4 in downtown L.A. The seeds for their 30-point Game 3 victory in Saturday night’s Game 3 were planted in the film room, after Ham and his staff had digested the moves Warriors coach Steve Kerr made before Golden State’s 27-point victory in Game 2.

For example, after Jarred Vanderbilt guarded Steph Curry for the first two games, the Lakers coach and his staff made a switch, putting the 6-foot-9 Vanderbilt on Draymond Green, having Anthony Davis guard JaMychal Green — the 6-8 small forward that replaced Kevon Looney in the Warriors’ lineup in Game 2 — and putting Austin Reaves on Curry, with Lonnie Walker IV emerging to get his turn as well.

The Lakers also went at Draymond Green offensively Saturday night. He got his fourth foul at the start of the second half and finished with two points and two rebounds and spent his (for him) terse postgame interviews complaining about the Lakers’ 37-17 free throw disparity.

Walker, who had been a starter and had gotten consistent minutes before the Lakers’ trading deadline changes, had seen his minutes drop to the point where he found himself working out after practices with what the coach referred to as the “stay ready” group, which also includes Shaquille Harrison, Tristan Thompson, Scottie Pippen Jr. and Cole Swider.

Going into Saturday, Walker had played 27 minutes in the team’s first eight playoff games. In Game 3 he played 24:24 and contributed 12 points, four rebounds and two steals, as well as a workout of a different sort chasing Curry around the court.

“Guarding Steph, I don’t care who you are. It’s not the funnest thing to do,” Walker said Sunday. “But I was ready, (playing) with the ‘stay ready’ group, Tristan, Shaq, Cole, Scotty, the list goes on and on. We’ve been in the gym night in and night out, competing against each other, having our own kind of playoff stay-ready thing. So it’s been really good. And I think the transition because of that really made it not so hard.”

Ham said he’d let Walker know the day before Game 3 that he’d likely need him, “and then doubled down on it after we had our film of Game 2, and he was ready. ... He was a starter for us at one point, so my confidence in him never wavered. It’s just different combinations of guys we were wanting to take a look at while we’re going through our process of getting to this point.”

Were there thoughts that the rookie head coach might be in over his head in a playoff series? If so, feel free to stow them. Part of the job is having a feel for whom to turn to and when.

When I asked Ham which of the guys he’d coached for had helped prepare him to navigate the ups and downs of a playoff series, the first two he mentioned were his head coaches as a Lakers assistant in the early 2010s, Mike Brown and Mike d’Antoni. And, of course, there was Mike Budenholzer, recently fired in Milwaukee two seasons after winning a championship. Ham assisted him for nine seasons in Atlanta and Milwaukee and only missed the playoffs once in that stretch.

The basics?

“Just going through the details, really understanding your opponent and what they like to do and what they don’t like to do and developing an initial coverage, a counter and then an escape plan, if you will,” Ham said. “And also knowing, you know, the combination of players that fit from series to series, understanding your rotation, understanding your coverages and understanding what you want to execute offensively. And you know, a lot of that came from Bud.”

We make so much of adjustments, but Ham noted that most of them take place early in a series. At a certain point — maybe tonight, maybe Game 5 in San Francisco Wednesday — there will be no surprises.

At that point, he said, “It’s just who does what they do the best, who has the energy, the effort and the urgency in terms of the little things: How you run it in transition, how you get back in defensive transition. Are you setting good screens? Are you playing downhill with force? Are you controlling the glass? Are you controlling the free throw line? And those things become important over trying to trick them with some type of play or some rogue defense the deeper you get into a playoff series headed towards seven games. It’s just the more disciplined you have to be and really consistent with the little things, the intangibles.

“It’s just that constant puzzle that you’re trying to figure out, that math equation and understanding what to plug in and what to not do.”

His players seem to trust his ability to push the right buttons. That, too, is part of the package.

“He’s putting us in the best position to thrive,” guard D’Angelo Russell said. “You got to respect the results. We’re in the second round, going to Game 4, and we have an opportunity to do something special.”

There’s still a long way to go in these playoffs. But this rookie head coach does not seem overmatched by any means.

jalexander@scng.com