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With unlimited transfers this season, match ups are more important than ever. The question is how to evaluate match ups, especially if you’re only an aspiring Armchair Analyst and not yet the real thing. The answer? Expected Goals (xG).
What are expected goals (xG)
The idea behind xG is simple. Every shot is awarded a probability of scoring based on the position on the field and the game situation, based on giant databases of shots from years and years of data. Then at the end of the game all the xGs from the individual shots are added up to generate the team’s xG for that game. This metric is a useful measure of the teams overall attacking or defending play, more so than just looking at how many goals a team has scored or allowed. If you’d like to learn more, there’s a nice video by MLS to explain further:
How to use these rankings
The rankings below use the xG metric to rank the match ups each week to help you determine which teams you should try to choose your attackers or defenders from. Each teams score is an average of their xG/g and their opponent’s xG/g separated out into offense/defense and home/away match ups. For example, this week New York Red Bulls play Toronto at home. New York Red Bulls’ average home xG/g is 1.65 and Toronto’s away xG/g allowed is 1.27 for an offensive xG score for Week 12 of 1.46 xG. The reverse can be done to calculate their defensive score for this week. The game by game xG numbers are taken from Ben Baer’s weekly xG article, and don’t include the xG from penalty kicks.
The first column is the team in the rankings, the second column is the teams opponent for this week (for double game weeks, both games are included separately), the third column is whether the ranked team is home or away, the fourth column is the the ranked team’s offense score this week (the higher the better), and the ranked teams defensive score (the lower the better). For reference, the average match up on the season has an offensive and defensive xG/xG allowed of 1.24 xG/g. So offensive scores higher than 1.24 and defensive scores lower than 1.20 are better than average match ups.
Week 12 xG Matchup Rankings
| Team | Opponent | H/A | OFF | DEF |
|---|---|---|---|---|
| Atlanta United | HOU | H | 1.74 | 0.86 |
| Chicago Fire** | DCU | A | 1.06 | 1.16 |
| Chicago Fire** | COL | H | 1.36 | 0.71 |
| Colorado Rapids** | CHI | A | 0.71 | 1.36 |
| Colorado Rapids** | PHI | A | 1.17 | 1.60 |
| Columbus Crew | NER | A | 1.13 | 1.75 |
| DC United | CHI | H | 1.16 | 1.06 |
| FC Dallas | SJ | H | 1.13 | 0.87 |
| Houston Dynamo** | ATL | A | 0.86 | 1.74 |
| Houston Dynamo** | PHI | A | 1.39 | 1.80 |
| LA Galaxy | MIN | A | 1.27 | 1.55 |
| Minnesota United | LAG | H | 1.54 | 1.27 |
| Montreal Impact | POR | H | 1.47 | 1.17 |
| NE Revolution | CLB | H | 1.75 | 1.13 |
| NY Red Bulls | TOR | H | 1.46 | 1.16 |
| NYCFC** | RSL | A | 1.49 | 1.07 |
| NYCFC** | OCSC | A | 1.27 | 1.14 |
| Orlando City** | SJ | H | 1.21 | 1.00 |
| Orlando City** | NYCFC | A | 0.86 | 1.29 |
| Philadelphia Union** | COL | H | 1.60 | 1.17 |
| Philadelphia Union** | HOU | H | 1.80 | 1.39 |
| Portland Timbers | MTL | A | 1.17 | 1.47 |
| RSL** | NYCFC | H | 1.07 | 1.49 |
| RSL** | SEA | A | 1.06 | 1.69 |
| San Jose Earthquakes** | OCSC | H | 1.30 | 0.79 |
| San Jose Earthquakes** | FCD | A | 0.87 | 1.13 |
| Seattle Sounders** | SKC | A | 0.91 | 1.38 |
| Seattle Sounders** | RSL | H | 1.69 | 1.06 |
| Sporting Kansas City** | SEA | H | 1.38 | 0.91 |
| Sporting Kansas City** | VAN | A | 0.87 | 1.01 |
| Toronto | NYRB | A | 1.16 | 1.46 |
| Vancouver Whitecaps FC | SKC | H | 1.01 | 0.87 |
Week 12 xG DGW Teams Matchup Rankings
This week I’ve also averaged the match ups for the just the DGW teams to give an idea of which are the best teams to choose from over the two match ups.
| Offense | Defense | |
|---|---|---|
| Chicago Fire** | 1.21 | 0.94 |
| Colorado Rapids** | 0.94 | 1.48 |
| Houston Dynamo** | 1.12 | 1.77 |
| NYCFC** | 1.38 | 1.10 |
| Orlando City** | 1.03 | 1.14 |
| Philadelphia Union** | 1.70 | 1.28 |
| RSL** | 1.06 | 1.59 |
| San Jose Earthquakes** | 1.09 | 0.96 |
| Seattle Sounders** | 1.3 | 1.22 |
| Sporting Kansas City** | 1.13 | 0.96 |
Week 12 rankings notes
- So for this week, the rankings for DGW teams suggests that:
- Offensively, Philadelphia, NYCFC, and Seattle have the top two game slates.
- Defensively, Chicago, Sporting KC, and San Jose have the top two game slates.
- From Philadelphia, NYCFC, and Seattle, the top players in xG + xA (American Soccer Analysis) on the season are:
- MID: Nicolas Lodeiro (5.03), Rodney Wallace (4.60), Jack Harrison (4.52), and Chris Pontius (3).
- FWD: C.J. Sapong (6.12), Clint Dempsey (5.44), and David Villa (4.61).
It doesn’t seem right to me that many of the xG numbers are symmetric. For example, the table has, in the row for Chicago’s game against Colorado, CHI’s xG at 1.36 and COL’s xGallowed at 0.71, but then in the line below, it has COL’s xG at 0.71 and CHI’s xGallowed at 1.36. Copy/paste mistake?
Hi Graham,
The rankings are necessarily symmetric. Each team is characterized by only two numbers each week. So in the case you bring up the numbers are Chi Home Offense, Chi Home Defense, Colorado Away Offense, and Colorado Away Defense.
So Chi’s Offense Score is Chi Home Offense/2 + Colorado Away Defense/2
Likewise Colorado’s Defense Score is necessarily the same as the Chi Offense Score
Colorado Away Defense/2 + Chi Home Offense/2
Does that answer your question?
I see, I didn’t understand, thanks Kyle. But I still wonder if there’s a copy/paste problem: shouldn’t the SEA/SKC and RSL/SEA games have symmetric data too?
Great catch, thanks. I had Seattle’s Home/Away games switched so they were using the wrong formulas. Its corrected now.