USMNT at Denmark: Beyond the score

By Jared Young (@jaredeyoung)

These three statistics help tell the story behind the latest USMNT result, and look beyond for big trends.

+7, -10. Those numbers represent the USMNT’s goal differential since the World Cup, split up by the first half and second half, respectively. A dominant first half has typically been followed by a more tragic second half coming out of the locker room. It’s well noted that the USMNT second-half defense is being criticized, but did you know that Johannsson’s second half goal against Denmark was the first goal the US team has scored in the second half since the World Cup? The late slump is not just a defensive concern.

Part of the issue could be that Klinsmann is playing less experienced players in the second half. That is somewhat true. Players who were on the World Cup roster have played 75 percent of all of the first half minutes. That number drops to 62 percent in the second half. But that overall percentage isn’t as experimental as it seems. The World Cup players have a strong presence, regardless of the half.

20.4%. The USMNT only squeezed off four shots against Denmark but managed to score on two of them. That extreme efficiency has been the trend more recently, and the World Cup players specifically have been blistering since July. Led by Jozy Altidore and his 44-percent finishing rate, the players on the World Cup roster have scored on 20.4 percent of the shots taken since the big tournament. Compare that to the 4.3 percent finishing rate of the new players on the team.

60%. (We’ll get to what this number stands for in a bit) I’m sorta kinda from New Jersey, and so is Alejandro Bedoya, so I’m probably supposed to root for him. But his persistent presence on the pitch for the USMNT continues to bother me. First, let’s talk about what I appreciate from Bedoya, and it’s well documented. His work rate is exceptional and his positioning is first rate. He’s a defensive minded midfielder that will do the dirty work and doesn’t look for the limelight. His defensive work against Denmark was critical in the first half as he sat deep enough to assist an otherwise sloppy back four. My trouble with him is that, from a playmaking point of view, he offers very little. And the US can’t afford to have players like Alejandro Bedoya play in the World Cup. For me, Bedoya is a stark reminder of the limitations of the team. As long as he is playing, I worry the US is not progressing as much as they need to during this cycle. The US struggled mightily to generate offense on the wings in the World Cup, and they simply have to upgrade that area to be a global force.

Bedoya is third on the team in minutes played since the World Cup with 409 minutes, behind only Mix Diskerud and Jozy Altidore. In the recent match against Denmark he was moved to the center of the midfield, where he typically plays at Nantes and where his lack of playmaking can be better hidden. So where does the 60 percent number come from?  That was the percent of Bedoya’s passes that were backward in the match. A typical team will pass 20-25 percent of their passes backward over the course of the game, and for a deep lying player 60 percent is way too much. Tack on the fact that the US was ceding possession and would have benefited from a more direct approach, and Bedoya’s backwards passing tendency becomes more of a glaring issue. Sorry my Jersey breathren, I’m looking for more in Russia.

To sum it up: The USMNT comes out extremely red hot in the first half, and somehow flips to an even more extreme cold in the second half, and that is what has everyone concerned. Experimentation is part of the problem, but protecting leads should be the key focus until it gets fixed. The players who played in the World Cup are very efficient right now in scoring goals, converting over 20 percent of their shots, while the newcomers are struggling in front of the net. I’ve also got my eye on Bedoya and I’m looking to see who is going to pass him on the depth chart, either on the wing or now at central midfield.

Brazil: better than you think!

Admittedly, it hasn't felt like Brazil has played all that well this World Cup.

The referee seemingly made its two-goal victory over Croatia a more relaxed finish than it should have been; against Mexico, the fourth-place team from CONCACAF, it only managed a draw; and Cameroon was just low-hanging fruit. The host team then took a lot of flak for its play in the Round of 16 against Chile, especially for its performance after halftime. Indeed, Brazil conceded a silly goal on a defensive giveaway, and Chile had chances to win that game.

But I'm here to tell you that Brazil has played better that it has looked. Too often, it seems, the scorelines heavily influence our praise and criticism of what's happening on the field.

Brazil dominated Group A in terms of Expected Goal Differential (xGD), and recorded the second-highest tally of any team during the group stage. Brazil's 1.05 xGD during even (tied) gamestates ranked fifth among the 32 teams. You might have expected better from the hosts, but most teams only played about 130 minutes in such gamestates. That's a big enough sample size to get a general idea of which are the best teams, but too small a sample to split hairs over the top five.

Croatia - June 12th

Against the Croats, a penalty awarded to Fred on what appeared to be a dive marred what was actually a solid performance by Brazil. Up to that controversial call, Brazil had earned 1.4 Expected Goals (xGoals) to Croatia's 0.4, dominating in quantity and quality of shots. Even after taking the lead on the penalty, Brazil still edged Croatia in xGoals the rest of the way, 0.30 to 0.24---a differential that matches what we'd expect of teams that were leading in this tournament.

Mexico - June 17th

Mexico is a better team than their last-second World Cup qualification (and that commentator) would suggest. It led the CONCACAF Hexagonal (the Hex!) in shot ratios and is currently ranked 13th in the world in the Soccer Power Index (though some of that improved ranking is because of their tie against Brazil). Despite a disappointing 0 - 0 tie on the scoreboard, Brazil's 1.4 xGoals again dwarfed that of its opponents. Mexico totaled just 0.5 xGoals.

Cameroon - June 23rd

There's not much to say about this one. Brazil's 1.9 xGD against Cameroon was the third highest discrepancy thus far in the tournament, trailing only France's drubbing of Honduras and Germany's handling of Portugal. It should be noted that both France and Germany enjoyed a man advantage for the majorities of those games.

Chile - June 28th

For Chile, the scoreboard and their well-developed rapport with the woodwork are clear indications that they could have won this game. However, the opportunity creation department informs us that Brazil probably should have won, as it did. 94 percent of this game's shots were taken during an even gamestate, either 0 - 0 or 1 - 1, and Brazil outpaced Chile during that time by a full expected goal. Even after halftime, when Brazil looked disorganized and sloppy, it still edged Chile 1.1-to-0.7 in xGoals.

Perhaps Brazil has not "looked" the part of tournament favorites during its first four games, but its shot creation numbers suggest it is definitely playing like one of the best teams. Add that to their pre-tournament resume, throw in the home-field advantage that's not going away anytime soon, and there is little doubt that Brazil is still the favorite to win this World Cup---maybe not with a majority of the probability, but definitely with a plurality.

The Manaus Effect

During the United States' game against Germany on Thursday, it was hard to go 10 minutes without hearing Ian Darke or Taylor Twellman mention Manaus and its effect on the players. The US Men's National team played its previous game against Portugal in the "Jungle City," as did Italy, England, Croatia and Cameroon, before each dropping three points in their next games.

Business Insider pointed out that those first four teams to play in Manaus lost by a combined score of 10 - 3, though it conceded the tiny sample size. A Washington Post article cited the same statistics, and pondered the possibility of a curse in Manaus. The Independent, based in the United Kingdom, noted on June 24th that each of the seven teams that played in Manaus lost its next game. That was confusing since only six teams had played in Manaus to that point, and only four of those had actually played a "next game." But whatever. #stats Graham Zusi, Sporting Kansas City's All-star midfielder and starter for the USMNT, wasn't having any of it, stating "I don’t think it was that bad to be honest. When it got down to it, at night it cooled off and the humidity wasn’t as bad. I think after about 24 hours the bodies felt great." Hugh Laurie would tell us that everybody lies, especially athletes on record, but there might be something to Zusi's statement. Below is a chart depicting the average temperature, humidity and heat index for each game site. The weather stats were taken from Weather Underground at the beginning of the second half of each game.

City	Games	Temp	Humidity	Index
Fortaleza	4	82.4	62%	85.4
Salvador	4	80.2	73%	83.5
Manaus	4	79.3	81%	82.1
Natal	4	78.5	83%	80.7
Cuiaba	4	78.4	66%	79.1
Brasilia	4	77.5	43%	78.7
Sao Paulo	4	69.4	55%	78.3
Belo Horizonte	4	76.1	40%	77.8
Recife	4	77.5	86%	77.8
Rio De Janeiro	4	75.7	71%	76.6
Porto Alegre	4	65.8	71%	75.5
Curitiba	4	64.0	79%	71.5

It's reasonable to theorize that more extreme environments take their toll on the human body, even professional athletes. But if we're going to get serious here, we need to consider all locales that were exceptionally uncomfortable. Manaus actually ranked third in average heat index, and had a lower average humidity than fourth-place Natal. Italy and England were the first to play in Manaus on June 14th and sparked the notion that it was a hell hole. But while they were duking it out in Manaus, Costa Rica and Uruguay were playing in Fortaleza, number one on that list up there. Though it was less humid to start the second half in Fortaleza, it was actually hotter, and Fortaleza's halftime heat index beat that of Manaus by a few points, 87.3 to 84.6.

It turns out that teams which most recently played in Natal, Salvador or Fortaleza---the other three extreme locations---did alright. Those teams outscored their opponents by a combined five goals. That makes it hard to believe that the conditions of Manaus were responsible for the downfalls of Italy, England and Croatia, though that still leaves the possibility of a non-weather-related curse.

To make this a legit study, there are some other factors we need to control for, and that is why God invented linear regression. Using ESPN's (Nate Silver's) Soccer Power Index, I controlled for each team's overall ability, and then I measured the effects of extra rest and past-game heat index on the goal differential outcome. The output is below:

Variable	Estimate	P-Value
Intercept	-0.37	15.8%
SPI Ratings Differential	1.01	0.1%
Additonal Days Rest (home)	-0.21	68.1%
Heat Index Differential	0.01	74.3%

If you're not a linear regression kind of person, then basically what that chart up there says is that neither the heat index of the teams' past games nor any rest discrepancy seemed to matter during this tournament. At least not in terms of goal differential. But we know that goal differential is finicky, and Expected Goals are a better indicator of team performance. Good thing we've got our World Cup Expected Goals data up and running! If we measure team performance by some Expected Goal Differential statistics (xGD), then we get these linear regression outputs:

Expected Goal Diff	Estimate	P-value	Even Expected Goal Diff	Estimate	P-value
Intercept	-0.06	61.9%	Intercept	0.01	88.4%
SPI Ratings Differential	0.46	0.1%	SPI Ratings Differential	0.34	0.2%
Additional Days Rest (home)	0.13	57.0%	Additional Days Rest (home)	0.17	37.0%
Heat Index Differential	0.00	79.7%	Heat Index Differential	0.00	86.3%

Again, regardless of whether we look at overall xGD or even-gamestate xGD, there are no statistically significant effects due to extreme heat index figures from past matches. Expected Goals data are obviously not a direct measurement of how heat impacts the athletes' bodies, but they should be a stable representation the teams' relative strengths during a match.

The Swiss were the last team (that is still in the tournament) to play in an 80+ heat index environment, but I wouldn't expect that to matter much based on what I've shown above. What will matter is that Argentina is much better. Talent has trumped the heat index so far this World Cup.

USA versus Ghana: Gamestates Analysis

In analyzing MLS shot data, I have learned that---with small sample sizes---how a team plays when the game is tied is a strong indication of how well it will do in future games. The US Mens National Team spent just four-and-a-half minutes tied Monday evening, the epitome of small sample sizes. In case you were curious, the US generated two shots during that time worth about 0.13 goals. Ghana did not generate a shot over those 4.5 minutes. The next most-important gamestate for a team is being ahead. With at least 17 games of data in MLS, knowing how well a team did when it was leading becomes an important piece of information for predicting that team's future success. Almost 95 minutes were spent with the US in the lead, a time in which the USMNT took six shots worth 0.5 goals to Ghana's 21 shots worth 1.7 goals.

Though MLS is definitely far below the level of even a USA-versus-Ghana match, I think a lot of the statistics from our MLS database still apply. I wrote a few weeks back about how away teams that were satisfied with the current gamestate went overboard with their conservative play. I think that could apply to the World Cup, as well. By most statistical accounts, USA versus Ghana was a fairly even matchup going in, yet the US played an annoying conservative style after going up a goal early. It gave up a majority of possession to Ghana in the attacking third, completing just 81 passes to Ghana's 171 in that zone---not to mention the US being tripled up in Expected Goals when it was ahead.

Granted, Expected Goals likely overestimates the losing team's chances of scoring. But not by much. In even gamestates in MLS, we see that teams are expected to score 1.29 goals per game, and they actually score 1.30 goals per game. Virtually no difference. However, when teams are ahead they are expected to score 1.79 goals per game, yet they only score about 1.60---an 11-percent drop. This discrepancy is likely due in large part to defenses being more packed in and capable of blocking shots. Indeed, teams that are losing have their shots blocked 27 percent of the time, while teams that are winning only have their shots blocked 22 percent of the time.

All that was simply to say that Ghana's 1.7 Expected Goals are still representative of a team that was in control---too much control for my comfort level. Even if we assume it was really about 1.5 Expected Goals against a defensive-minded American side, that still triples the USA's shot potential. Either the US strategy was overly conservative, or Ghana is really that much better. I'd like to believe in the former, but it's picking between the lesser of two evils.

It just doesn't make sense to me to play conservatively to maintain the status quo. It invariably leads to massive discrepancies in Expected Goals, and too often allows the opposition an easier way to come back.