Michael Giberson
In a follow-up to my World Cup posting comparing hype and data on the new Adidas Teamgeist soccer ball design, I've taken another look at the Major League Soccer data. You may recall that the new ball was supposed to be a striker's dream and a goalkeeper's nightmare. In fact, the Washington Post had quoted DC United goalkeeper Troy Perkins saying exactly that about the new ball: "a nightmare, an absolute nightmare."
The World Cup data didn’t reveal a scoring boom. I wrote in July:
But the numbers generated by the 62 games played so far suggest little effect on overall performance. There have been 1458 shots taken in the 2006 tournament so far, of which 674 have been on target (46.2 percent). Goalkeepers have recorded 474 saves, amounting to just over 70 percent of shots on target.Compare those numbers to the results through the 64 games of the 2002 World Cup: a total of 1423 shots, of which 689 were on target (48.4 percent). Goalkeepers made 451 saves, which constitutes about 65 percent of shots on target.
Average goals per game are down as well, dropping to 2.23 goals in 2006 so far compared to 2.51 per game in 2002.
So, with MLS teams now having played 29 games each with the new ball, how's that nightmare going?
To date in 2006, both the average number of shots and the average number of shots on goal per game are down slightly in MLS games. The percentage of shots that produce a goal has fallen just a bit, too. The average number of goals per game has fallen about 12 percent, from 2.87 in 2005 to 2.53 in 2006. I don’t have complete goalkeeping stats handy, but comparing 2006 to 2005 league leaders for saves as a percent of shots on goal suggests that saves percentages are up from last year in the MLS.
It would be useful to look back more than one year, and also to analyze the numbers more carefully, but in any case it sure isn’t obvious that the ball has made life more miserable for the league’s goalkeepers.
And how about Troy “absolute nightmare� Perkins? He’s leading the league with a 1.11 Goals Against Average.
NOTE: I failed to notice when posting the picture above that the ball in the picture is an "official replica" Adidas Teamgeist ball, rather than the true, new, high tech ball used in World Cup and MLS this year. A little inspection of the picture reveals the familiar hexagon and pentagon patterns of the typical 26-panel soccer ball. Wikipedia has more on the ball. (The Encyclopedia Brittancia online seems not to have an entry on it.)
The new ball may be a nightmare for goalkeepers, and result in fewer goals.
You can divide goals into two categories: Shots that the keeper can't reach, and goalkeeping errors - where the keeper could have reached the ball but misjudged it.
If the flight of the new ball is less predictable, it will increase the frequency of goalkeeping errors - and those are what goalkeepers have nightmares about.
But at the same time, it will decrease the frequency of unstoppable shots - the balls placed precisely in the top corner from 30 yards, or the crosses that perfectly pick out the striker half a pace ahead of his marker on the edge of the 6-yard box.
In top-level play, most goals are good shots rather than goalkeeping errors, and the increase in goalkeeping errors will be cancelled out in the statistics by the decrease in unstoppable shots. But they won't be cancelled out in the nightmares. One badly-misjudged ball can be defining of a career.
It would just be terrible if there were any soccer games that were not 0-0 ties.
Andrew is right about how a less predictable flight would affect both shot quality and goalkeeper errors. "Less predictable" is not the Adidas party line, rather they presented it a good for striker control, but it may be the actual effect of ball design changes in play.
If the ball is less predictable, should we expect:
Fewer assists (because harder to serve up a ball on target)?
More balance in time of possession (because harder to maintain ball control)?
More penalty kicks become goals?
Goalkeeper blocking shots more often than catching shots (because harder to catch safely)?
Fewer goals scored off a free kick to header combination, relatively more free kicks as shots or played to the feet of a teammate?
All suggestions are just rather loose speculation on my part, and probably requiring professional quality data to examine properly, but MLS and other leagues and tournaments likely have access to the data and an interest in the answer.
Anyone know of better attempts to answer this question? What sort of data did Adidas offer when it sold the World Cup on the new ball?
What I've noticed is that the ball seems to "wobble" mid-flight somewhat, but only when struck very hard and without a lot of spin being applied, mostly you see it on shots from distance during the run of play.
So I don't think assists will be affected at all, as most crosses are affected by the spin applied and don't seem to wobble. Obviously ground passing is not affected.
Also, things like penalty kicks or ball possession are unaffected, the ball doesn't really do anything different than before except on long shots that are allowed to "knuckle". Close range shots or passes are not more difficult to control, the ball is not that erratic.
I think that goalkeepers in the WC were often forced to parry balls that they would've otherwise caught because of the unpredictable dipping and swerving. I remember seeing a couple of instances where that was almost certainly the case.
In my opinion it's a wash since most of the world's best players know exactly where they want to put the ball and how to get it there when they strike from distance. So if the ball is doing something unpredictable it can just as often lead to a save or a miss as to a goal.