Climbing the Ladder: Who scores most important goals?

The race for the 2011 Golden Boot is one of the most wide open in league history, as 17 players are bunched up with eight to 12 goals apiece. It’s easy to look at the statistics page and see all the leaders, but it’s harder to know the answer to the following question: Whose goals this season have been the most important for their team?

There’s game-winning goals, a stat which has been found easily for years. However, it depends more on what happened after the fact rather than the score when the goal occurred.

Toronto FC vs. Colorado Rapids
Score Minute Team Player PPG Before PPG After Diff.
1-0 52 TOR Koevermans 1.51 2.35 0.85
2-0 60 TOR Koevermans 2.41 2.84 0.43
2-1 70 COL Nyassi 0.18 0.36 0.18

For example, if a player scores to put his team up 3-0 in the 79th minute and the game ends 3-2 (like Adam Cristman did last year for D.C. United at Seattle), then he’ll be credited with the game-winning goal, even though the first two may have been more important.

So what’s the best way to determine how important each goal is?

In baseball, there’s a statistic called Win Probability Added. By calculating the chances each team has of winning the game in every situation, it can be determined exactly how much each play changes the odds of the game. Each at-bat, each hit, each stolen base — All are given a value. When a game is complete, it’s then possible to know exactly what the most important plays were that mattered the most.

In soccer, it’s impossible – at least for now – to measure every single action on the field with that level of detail. But it is easy to figure out how goals impact the odds of winning by using the data for every MLS game of 2011.

By breaking down all 257 regular-season games and figuring out the score in every minute for each one, it’s possible to know what the exact points per game (PPG) number is for any margin at any moment. Using this, it’s a snap to determine how many points each goal was worth.

Let's start with the table that breaks down Toronto's 2-1 win over Colorado last weekend (above at right).

The average PPG for home teams who were tied after the 51st minute is 1.51 so far this season in MLS. For home teams who led by one goal after the 52nd minute, the PPG was 2.35. Subtracting the before PPG from the after means that Danny Koevermans’ first goal was worth 0.85 points. It also makes it the most valuable goal of the game, despite his second actually counting as the game-winner after Sanna Nyassi pulled one back for the Rapids.

Leading Scorers in MLS This Season
Player Team Goals Pts. Avg. GWG
Mendoza CLB 11 8.36 0.76 4
Wondolowski SJ 10 7.95 0.80 3
Donovan LA 12 7.54 0.63 4
Shea DAL 10 7.28 0.73 5
De Rosario DC 9 7.24 0.80 2
Kamara SKC 8 6.90 0.86 1
Davies DC 11 6.90 0.63 3
Henry NY 12 6.46 0.54 3
Hassli VAN 10 5.70 0.57 0
Joseph NE 8 5.47 0.68 3
Fernandez SEA 8 5.07 0.63 2
Bravo SKC 8 4.75 0.59 2
LaBrocca CHV 8 4.57 0.57 1
Saborío RSL 8 4.16 0.52 4
Camilo VAN 8 3.63 0.45 1
Maicon Santos DAL 8 3.12 0.39 1

Using the same method, the table at right shows how the top 17 goalscorers this season stack up with the combined total amount of points their goals have been worth. The leaders in each category are in bold.

We can see that New York’s Thierry Henry is tied for the most goals with LA's Landon Donovan, but Henry doesn’t rank near the top of this chart. That’s in part due to having two goals which counted for zero points: His first to put the Red Bulls up by three in the 87th minute at home against San Jose on April 16, and his 10th, which was a consolation goal when they were losing 4-0 away to Colorado on July 20.

Despite only having one game-winning goal, on average, Kei Kamara’s goals have actually been the most important. Why? Five of his eight tallies have put Sporting Kansas City into the lead. Unfortunately, their record in the games where those five took place is two wins and three losses, simply because Sporting's defense has struggled mightily to hold the lead this season. Still, his eight goals have been more valuable than Henry’s 12, on average.

But look again at the name at the top of the chart. If there was a most valuable boot, the Columbus Crew’s Designated Player Andrés Mendoza would currently be the front-runner, as he leads the league for most total points added. He’s scored 10 of his 11 goals at home, which certainly helps.

Andrés Mendoza's Goals This Season
Goal Date Game Score Minute PPG Before PPG After Points
1 4/1 DAL 1-0 54 1.45 2.42 0.97
2 5/28 CHV 1-1 17 0.96 1.68 0.72
3 5/28 CHV 2-2 52 0.68 1.49 0.80
4 6/8 RSL 1-1 76 0.39 1.26 0.87
5 6/18 HOU 1-0 41 0.96 1.70 0.74
6 6/26 COL 2-1 18 1.68 2.29 0.61
7 6/26 COL 3-1 48 2.25 2.85 0.60
8 8/20 PHI 2-1 51 1.53 2.37 0.84
9 9/10 TOR 2-3 87 0.07 0.21 0.14
10 9/14 HOU 1-1 64 0.54 1.42 0.88
11 9/14 HOU 2-1 76 1.24 2.44 1.20

Located above is a breakdown of when Mendoza has scored his goals this season, and it's clear to see that he tends to find the back of the net during close games. Only one of his goals this season was largely irrelevant, when he brought Columbus back to a 3-2 deficit with a goal in the 87th minute against Toronto FC on Sept. 10.

No matter. The Reds got a stoppage-time goal from Koevermans to seal the 4-2 win.