This is the third season of BttP’s prediction and projection tracking, and once again we’re bringing you our All-Star Break check-up on the teams that have most confounded the preseason expectations. Below are three teams that have most overperformed their projections, three that have most underperformed, and some crack analysis of how this has happened, whether it will continue, and an extremely ill-advised revised prediction for the end of the year.

Top Overperformers

Arizona Diamondbacks (53-36, .596 winning percentage)

BttP Prediction: 77 wins (.475)

Composite Projection: 78 (.484)

On Pace: 96

On Pace by Projection: 88

Third Order Winning Percentage: .595 (-.001 difference from actual)

The Diamondbacks seem to have gone from the subject of much derision to playoff contenders in an extremely short space of time, and it doesn’t look like a fluke. They’ve scored over 100 more runs than they’ve allowed, and any of the expected winning percentage metrics you can find suggest that their win total is entirely warranted, perhaps even a little low.

Paul Goldschmidt has been worth four wins already and is a leading contender for MVP, Jake Lamb has cemented himself as an elite offensive threat in the heart of the lineup, and they have a chance to be the best baserunning team of all time. With Zack Greinke‘s rebound to the kind of form Arizona paid him for and Robbie Ray‘s step forwards, there’s a formidable one-two at the front of the rotation, with Zack Godley and his excellent curveball offering some depth that few expected. Even with the Rockies fading slightly, the problem is that the Dodgers are the best team in the NL, so Arizona are probably going to have to negotiate the wild card game to get a full playoff series. At least they’re almost certain to get there now.

Revised Prediction: 91-71, second place.

Houston Astros (60-29, .674)

BttP Prediction: 90 (.556)

Composite Projection: 92 (.565)

On Pace: 109

On Pace by Projection: 101

Third Order Winning Percentage: .684 (+.010)

Much like 2016, the Astros were clear favourites among predictors and projection systems alike, with the attractive combination of a very deep lineup and a relatively weak-looking division behind them. Unlike 2016, Houston has lived up to expectations and then some, crushing any hopes their divisional rivals might have had of an AL West title to sit 16 1/2 games clear of the Angels and Rangers at the break. This looks like the juggernaut the team was hoping to assemble when they were busy tanking for draft picks.

Most days it’s hard to find a bat in the lineup that’s even slightly below-average, and in Jose Altuve, Carlos Correa, and George Springer, they have three that could be worth six-plus wins by the end of the year. The team rarely strikes out by modern standards, with the rather unfair combination of the league’s lowest K% (17.3%) and the highest slugging percentage (.500). Dallas Keuchel has returned to 2015 Cy Young form, albeit with some injury concerns, while Lance McCullers has given the team a second starter of high quality and looks as though he may be the ace that many hoped he would be. They’ve also had the best bullpen in the league, led by Chris Devenski, who is frequently used for multiple innings. Not claiming home field advantage would be a massive disappointment and the only glaring question is whether they have a third starter they can count on for the playoffs, or whether it even matters with this collection of relievers.

Revised Prediction: 102-60, first place.

Milwaukee Brewers (50-41, .549)

BttP Prediction: 74 (.457)

Composite Projection: 73 (.453)

On Pace: 89

On Pace by Projection: 84

Third Order Winning Percentage: .503 (-.046)

The Rockies actually had an edge of a single point over the Brewers when compared to the composite projection, but as Milwaukee also outperformed the BttP prediction by some margin and received considerably less consideration from anyone for a playoff spot in the preaseason, they got the nod here. Unlike the other two teams, the Brewers are outperforming some of their record estimators, most notably that third order record, and they’re also two wins better than their BaseRuns record. However, they do have a plus-45 run differential and their Pythagorean record is identical to their actual.

The Brewers’ young and frequently strikeout-prone lineup might be the most likely of all the outperformers to go on a cold stretch and sink the team. Keon Broxton is pushing the limits of acceptable strikeout numbers with a 37.9% rate, making the likes of Jesus Aguilar and Domingo Santana look like contact hitters, but all three have been valuable parts of this surprising run so far. Eric Thames has cooled off considerably after looking like the best hitter in the league in April, but he’s still an on-base machine with 23 home runs. Third baseman Travis Shaw is their best position player right now with around three WAR by every site’s reckoning, a fact which presumably has just made every Red Sox fan cry a little. It’s the rotation which is of real concern. Although Jimmy Nelson‘s breakout is thoroughly supported by his peripherals, an oblique injury to Chase Anderson and the lack of almost anything else behind him means it’s still hard to project the Brew Crew for first place, even with a 5 1/2 game lead at the break. At some point we have to stop saying the Cubs will come around, but we aren’t there yet, and even a continuation of this pace doesn’t make Milwaukee a 90-win team.

Revised Prediction: 83-79, second place.

Top Underperformers

San Francisco Giants (34-56, .378)

BttP Prediction: 90 (.556)

Composite Projection: 88 (.544)

On Pace: 61

On Pace by Projection: 73

Third Order Winning Percentage: .365 (-.013)

The Giants were in the other half of this piece last year following a blistering first half that left them with the best record in baseball. Since then they’ve been one of the worst teams in the league, limping into the playoffs in 2016 and then failing to even finish the first half of 2017 ahead of the Padres. They’re 64-98 over the past year. There’s nothing particularly undeserved about this record: San Francisco has been outscored by 99 runs and only those Padres and the hapless Phillies have crossed the plate fewer times.

While it sometimes feels like Buster Posey is alone in providing any offensive value for the Giants, the likes of Brandon Belt and Joe Panik haven’t been completely unproductive. More problematic is the almost complete evaporation of Hunter Pence‘s power and Brandon Crawford‘s paltry .266 OBP. It gets even worse with the rotation, which looked like it had two aces in Madison Bumgarner and Johnny Cueto, backed up by Jeff Samardzija and Matt Moore. Instead, only Samardzija has approached an acceptable level of production, and even his performance is frustrating, with a stellar K/BB ratio of over 9 but an ERA of 4.58. Bumgarner’s dirt bike accident and Cueto’s loss of both control and the ability to generate ground balls have rendered the rest of the staff almost replacement-level. The less said about Moore the better. Mark Melancon failed to make the ninth inning any less dramatic than it was last year, and is now hurt. Although Bumgarner will be back soon and the likes of Crawford have a track record of much better performance, many others will be leaving AT&T soon and this may not get much better. The Padres are bad too, though.

Revised Prediction: 67-95, fourth place.

Philadelphia Phillies (29-58, .333)

BttP Prediction: 71 (.438)

Composite Projection: 73 (.448)

On Pace: 54

On Pace by Projection: 63

Third Order Winning Percentage: .379 (+.046)

The Phillies looked to be trending in the right direction, with 8 more wins in 2016 than 2015, some good trades that brought in a collection of promising young talent, and the discovery of surprise players like Odubel Herrera adding to the more highly-touted youth on the major league roster such as Maikel Franco and Aaron Nola. That direction has very much reversed and Philadelphia is now the clear favourite for the number one pick in next year’s draft, with only the Giants really threatening to take that away from them.

There are still bright spots for this year’s Phillies: Aaron Altherr has returned from injury to be a significant offensive contributor; Herrera appears to be an exceptional center fielder by both more traditional fielding metrics and Statcast data;  Nola has shown on occasion that he has the potential to be a very good starting pitcher, and his ERA of 3.59 is actually significantly better than league average in this inflated offensive environment. There’s a lot more to be concerned about, though. Herrera seems to have lost all of the plate discipline that characterised his success with the bat last season. Franco has been one of the worst regulars in the majors this year, at -0.5 fWAR, and is apparently declining rather than improving with experience. Even the most promising minor league talent has disappointed, with top prospect J.P. Crawford hitting a shocking .211 at Triple-A, even if he is still displaying excellent plate discipline. There’s plenty of time for the Phillies – no-one expected them to contend for anything this year – and much of this can change, like Franco’s .215 BABIP. In 2017, not losing 100 games would count as a win.

Revised Prediction: 61-101, last place.

Chicago Cubs (43-45, .489)

BttP Prediction: 97 (.599)

Composite Projection: 95 (.585)

On Pace: 79

On Pace by Projection: 86

Third Order Winning Percentage: .533 (+.044)

Let’s be honest, you were going to be surprised if the Cubs weren’t here. There was considerable scorn cast upon PECOTA when the Dodgers were given 8 more wins than the 91-win Cubs in the initial run; the surprising outcome now will be if Chicago gets that close to LA. Instead of a comfortable cruise to another divisional title, the champions now have to overturn that 5 1/2 game gap to Milwaukee, and will have to play like a 102-win team the rest of the way just to crack 90 wins.

Of course, Chicago won 103 games last year, and most of that team is still in place. The fact remains that the Cubs have simply been decidedly average in 2017. Their run differential is zero, their record is almost .500, and they’re middle of the pack in batting, pitching, and fielding (although BP’s Park Adjusted Defensive Efficiency does rate them as fourth in the league). Going from one of the best defensive performances in baseball history to anything other than elite still represents a fairly significant decline, and outside of Kris Bryant and Anthony Rizzo, they really haven’t got another hitter who can be considered even above-average thus far.

The inevitable BABIP regression tied to that defensive performance has caused problems for the pitching staff, but even outside of that, their peripherals just aren’t all that impressive. Homers have been a problem for most of the starters, especially John Lackey, and while we’ve seen Jon Lester, Jake Arrieta, and Kyle Hendricks perform at an elite level in very recent history, none of them can be called elite on the basis of their 2017 season. Nonetheless, this is still a team with two outstanding hitters, talented youngsters with room to grow, some exceptional defensive ability, and a pitching staff with a superb track record. Even as late as July, projections are still more predictive than in-season performance, but the Cubs are doing their best to test our resolve in sticking to them.

Revised Prediction: 86-76, first place.