At the halfway point of the 2019 MLS regular season, there are teams underperforming, overperforming, and just performing. What about the teams that have shown real improvement? And is there a common thread that ties them together?

To me, there's a clear connection among most of the most improved teams.

5. Minnesota United

When you add the 2017 MLS Defender of the Year plus one of the five best defensive midfielders in league history, you’re almost guaranteed to be a little better. After finishing 2017 and 2018 with 1.06 points per game, Minnesota are on pace for 1.31 points per game this season. They are also scoring more goals per game (1.4) and conceding fewer (1.56). With that said, their playoff spot is far from secure. All of the teams below the Loons pose a threat — Portland have a stretch of home games, Sporting are starting to get healthy again, and Colorado, RSL, and Vancouver have all seen an uptick in performances. Minnesota are definitely better than the two previous seasons, but they can’t get complacent.

4. New England Revolution

The Revs went 5-17-6 with a minus-31 goal differential over the 28 games from July 14, 2018 until May 8, 2019. In the five games since, they have gone 2-0-3 with a plus-three differential. It’s still a small sample size, but the improvement is clear. Bruce Arena (with an assist to interim coach Mike Lapper before him) has turned the Revs’ ship around. He’s simplified the playing style and given the players more autonomy on the field. In doing so, he has pretty much everyone on the team playing well. Given every team in the East seems to have Jekyll-and-Hyde tendencies, there’s no reason the Revs can’t mosey their way above the playoff line with their newfound consistency.

3. Orlando City

The Lions put together a historically bad season in 2018, so there wasn’t exactly anywhere to go but up. To their credit, however, they have made up a lot of ground. Their offseason work proved to be astute — Nani, Ruan, Robin Jansson, Joao Moutinho and Sebastian Mendez have all been good acquisitions. James O’Connor also has made tough decisions and relegated a few big stars. Orlando have become one of the most no-nonsense, hardest working teams in the league. If they can get a little more quality in the final third, particularly from Tesho Akindele, Chris Mueller, and Dom Dwyer, then the Lions have a real shot to make the playoffs for the first time in their MLS history.

2. LA Galaxy

When you have Zlatan Ibrahimovic up top, it’s an almost certainty that you’ll win games as long as you don’t leak goals. Unfortunately, the Galaxy didn’t just leak goals in 2018, they gushed them. That’s stopped in 2019. New boss Guillermo Barros Schelotto arrived in LA and focused on the team’s defending and it’s worked. They have given up almost a goal per game less this season. They have some tweaks to make when they are in possession, but if they can make those adjustments, the Galaxy pose a real threat to LAFC in the West.

1. San Jose Earthquakes

What a difference a few months can make. Do you remember the Quakes last season? Do you remember the Quakes in April?!? Watching San Jose in the first five games of the year felt like the moment in the movie when everyone in the movie theater knows the bad guy is about to get the main character except the main character himself. In the most recent 10 weeks, though, San Jose have turned into a free-wheeling, swag-stepping, dream-stomping monster. They can kick you off the field, as Bob Bradley attested to last week, or pass the soul out of you:

The Quakes are must-watch IMO pic.twitter.com/EgUIJ3QI0L — Matthew Doyle (@MattDoyle76) June 27, 2019

The Quakes haven’t just been playing like a playoff team lately; they’ve been playing like a real trophy contender. Up next on their schedule: the Cali Clasico against the Galaxy on Saturday (10 pm ET | MLS LIVE on ESPN+; DAZN in Canada).

And now for the cloth that ties these teams together. Four of the five teams have signed a new head coach in the last 12 months. Some, like Orlando’s James O’Connor and Matias Almeyda, took some time to show a worthwhile difference. Others, like Arena and Schelotto, brought the juice right away.

It’s another reminder, if another reminder was needed, about the importance and power of coaching in soccer. Coaches matter more than players. A good coach can maximize the level of his players more than a good group of players can make up for the wrong coach.

The Earthquakes are trotting out almost the exact same starting XI in 2019 as they did in 2018. That group of guys went from enduring the 2nd worst season of this decade to legitimately pounding teams. Ditto for the Revs, who haven’t added a single player in the transition from .75 points per game to 1.8 ppg. One factor has changed: the head coach.

Players make the plays, as Arena constantly reminds us. But you can’t make the play if you aren’t in the right position or the right frame of mind — the coach determines those things. Most players aren’t definitively good or bad; they play well or poorly depending on the situation they are in.

This isn’t to say that a coach who fails with a team is a bad coach. Good coaches can do a poor job in the same way good players can have a bad season. Fit matters. A single experience doesn’t define a coach.

It’s becoming increasingly clear, however: The biggest signing your team makes is the one at the top.