LSU’s defense in 2020 was defined by how porous it was.

It gave up an awful lot of big plays and an awful lot of points.

It was the primary weakness on a team that slipped to a 5-5 record after winning the national championship the previous season.

Tigers head coach Ed Orgeron has done a lot to try and fix the defense. He replaced coordinator Bo Pelini with Daronte Jones.

He replaced defensive line coach Bill Johnson with Andre Carter.

He brought in new linebackers coach Blake Baker.

And cornerbacks coach Corey Raymond stayed, as did several players who could have turned pro.

Some young players who were thrust into more prominent roles than they were ready for last season experienced growing pains but saw their development accelerated in the process.

The No. 3 recruiting class in the country features several highly-regarded defensive players.

LSU has done a lot of stuff to make the defense better in 2021 and there is reason to believe it will be better.

There is also the reality that the defense has to be significantly better if the Tigers are going to contend in the SEC West.

Here are 5 things that will define LSU defensively in 2021:

1. How well the players blend into Daronte Jones’ defense

Pelini’s defense and last season’s players were a bad mix.

Jones knows he, his defense and his players have to mesh together much better.

His chances for success begin with his ability to get the players to believe in him and his system, to put each player in a role that best fits the player’s physical and mental skills, to teach the players well enough that they are comfortable and confident with their ability to excel in their role and contribute to the defense’s overall success.

The defense played very well in the spring game, though that doesn’t guarantee much for the fall.

But Orgeron seems to believe that these players already have bonded better with Jones and his defense than last year’s players bonded with Pelini and his defense.

That might be true, in part, because Jones had spring work that was denied Pelini because of COVID-19.

Regardless of the reasons, Jones has to be a better fit than Pelini was.

2. Can the Tigers reduce the frequency of big plays allowed?

This will be a lot easier if the players have a better understanding of the defense and the increased level of comfort and confidence that comes with it.

LSU victimized itself with virtually every type of breakdown imaginable last season. At times, the Tigers were undisciplined. They made mental mistakes. They lost one-on-one battles. They couldn’t shed blockers, cover receivers and tackle ball carriers consistently well enough.

It wasn’t just 1 or 2 shortcomings; it was a meltdown.

LSU has to cut down on each of the aforementioned breakdowns. If offenses have as many big plays and score as easily, quickly and frequently as they did last season, the defense and the team will struggle just as much.

3. Can they generate a consistent pass rush without blitzing?

One trademark the best SEC teams perennially have is dominant defensive fronts.

They have depth charts overflowing filled with big, strong, quick athletic linemen who can dominate the line of scrimmage, stop the run and consistently knock offenses off schedule, and pressure the quarterback consistently enough to disrupt the passing game.

LSU has had that in the past. It didn’t have it last season.

But the Tigers do seem to have the ingredients, including a useful blend of experience and youth, to win the line of scrimmage without having to consistently divert resources from the back of the defense to do so.

That potential needs to become a reality.

4. Will the linebackers continue the progress they showed in the spring?

When spring practice began, Orgeron was concerned about the relative lack of experience at linebacker. On multiple occasions during the spring, he said he was seeing the development that he craved.

That must continue during the summer and preseason camp, then carry over into the regular season.

LSU doesn’t necessarily need an individual to have an impact similar to Devin White or Deion Jones, though that would be nice.

The Tigers need a consistently reliable unit that doesn’t feature a significant weakness in the run defense or pass defense that offenses can target with the expectation of exploiting it.

5. The turnovers they can create, especially in the secondary

LSU made some big plays on defense last season, including Eli Ricks’ pair of pick-6s and 1 each by Jay Ward and Jabril Cox. But the defense didn’t make nearly enough big plays to negate the ones it allowed. LSU’s defense gave up more 40-yard plays (24) than everybody else in the SEC. Alabama only allowed 12 such plays — and played 3 more games.

A reduction in big plays allowed obviously would make it easier to balance the scales, but the Tigers have the playmakers in Derek Stingley Jr. and Ricks, especially, to tip those scales significantly in their favor if they can slow down run games, get teams into obvious passing downs, and pressure the quarterback with or without blitzing.

What LSU needs to do isn’t anything unique, but it is stuff that rarely seen last season.

MORE LSU: 5 things that will define the Tigers’ offense in 2021