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Goal-keeper Math

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I hope you enjoyed your dose of fashion talk and pretty, pretty pictures last week, because today we’re diving into the deep end of statistical analysis. Goal-keeping statistical analysis, to be precise. Climb aboard as we look at some figures and try to answer the question of whether Bayern really needs a new goal-keeper.

First, a disclaimer: numbers obviously can’t capture the entire story of a match or player.  A keeper might face 6 straight shots directly at his chest.  If you look at the numbers, you’d say “oooh, 6 straight saves!” but any competent keeper would have made those saves.  Similarly, the opposing team might only put 3 shots on target the entire game, but 2 may have been completely unsaveable even for the best goalkeeper in history (for instance, if the CB missed a tackle or took a bad angle, and the striker just had to tap the ball into an open net).  The numbers say your guy allowed 2 goals on only 3 chances, but really he didn’t play as badly as that ratio would suggest.

 

Kraft is good.  Is he good enough?

Kraft is good. Is he good enough?

 

But even with these disclaimers, I do think that goal-keeping statistics can be valuable over the course of a long season.  The degree of difficulty from one shot to the next may vary widely, but once you get to large sample sizes (anything over 10 games) I imagine the ratio of easy vs. somewhat hard vs. very hard saves is fairly similar across keepers.  With that in mind, we decided to look into some numbers from this season to answer the question posed above.  And (with numerous qualifications), we’re forced to conclude that the answer is “yes.”

THOMAS KRAFT

First things first - I like Kraft.  I think he’s a good keeper and a hard-working young guy.  I like the fact that he came up through our youth club.  His penalty save in our last match vs. Freiburg may have saved our chances of playing Champions League ball next.  That said, let’s look at his numbers.

 

Date Opp Comp Shots faced SOG faced Goals allowed
Nov 23 AS Roma CL - Group 17 10 3 (1 pen)
Dec 8 Basel CL - Group 10 4 0
Jan 15 - starts here VfL Wolfsburg BL 10 4 1 (+1 pen blocked)
Jan 22 Kaiserslautern BL 13 6 1
Jan 26 Alemannia Aachen Pokal 6 1 0
Jan 29 Werder Bremen BL 9 4 1
Feb 5 Koln BL 17 6 3
Feb 12 Hoffenheim BL 14 4 0
Feb 19 Mainz BL 18 7 1
Feb 23 Inter CL - Rd 16 13 4 0
Feb 26 Dortmund BL 16 5 3
March 2 Schalke Pokal 9 2 1
March 5 Hannover BL 13 7 3
March 12 Hamburg BL 10 3 0
March 15 Inter CL - Rd 16 15 3 3
March 19 Freiburg BL 12 4 1 (+1 pen blocked)
2010-2012 TOTALS 202 74 21

 

All the math is mine, so I apologize if I made a mistake. 

As you can see, Kraft got only occasional duty until January, when he took over for good.  He had a couple really good games, and a few not so good ones.  The most-recent Inter game wasn’t his fault, although in a strict numerical sense, 3 goals on 3 shots on target is a clunker.  He’s allowed 3 goals on 3 other occasions, too.  

Overall, Kraft has played 16 games this season, allowing 21 goals on 74 shots on goal.  This gives him a save percentage for on-target shots of about 71.6%. 

If you count all shots faced, he did not allow a goal (either through a save or otherwise) on 181 of 202 shots faced, meaning about 89.6% of the time the opposing team cranked up a shot, they failed to score.

He also completely blanked the opposition on 5 occasions out of 16 games, giving him a clean-sheet percentage of about 31% (just under a third).

MANUEL NEUER

One of our main transfer targets is said to be Schalke keeper Manuel Neuer.  Although he just turned 25 yesterday, Neuer has a lot more experience, having been the regular starter at Schalke for 5 years already and the starting keeper for Germany this past World Cup, allowing only one goal throughout 3 group-stage games.

This season, as the starter since opening day, Neuer gives us more to work with:

 

Date Opp Comp Shots faced SOG faced Goals allowed
Aug 16 AfR Aalen Pokal 6 3 1 (pen)
Aug 21 Hamburg BL 18 6 2
Aug 28 Hannover BL 11 4 2
Sept 10 Hoffenheim BL 23 8 2
Sept 14 Lyon CL - Group 16 5 1 (own goal)
Sept 19 Dortmund BL 23 12 3
Sept 22 Freiburg BL 8 1 1
Sept 25 Gladbach BL 11 6 2
Oct 2 Nurnberg BL 10 4 2
Oct 16 VfB Stutt BL 12 7 2
Oct 23 Eintracht Frankfurt BL 17 1 0
Oct 26 FSV Frankfurt Pokal 7 1 0
Oct 30 Bayer Leverkusen BL 11 3 1
Nov 2 Hapoel Tel Aviv CL-Group 8 3 0
Nov 5 St. Pauli BL 6 0 0
Nov 13 VfL Wolfsburg BL 17 4 2
Nov 20 Werder Bremen BL 10 2 0
Nov 24 Lyon CL-Group 12 7 0
Nov 27 Kaiserslautern CL 15 8 5
Dec 4 Bayern Munich BL 17 5 0
Dec 7 Benfica CL-Group 22 3 1
Dec 12 Mainz BL 7 4 0 (+1 pen block)
Dec 18 Koln BL 6 1 0
Dec 21 FC Augsburg Pokal 6 3 0
Jan 15 Hamburg BL 9 3 1
Jan 22 Hannover BL 11 4 0
Jan 25 Nurnberg Pokal 11 6 2
Jan 29 Hoffenheim BL 16 6 1
Feb 4 Dortmund BL 20 8 0
Feb 12 SC Freiburg BL 3 1 0
Feb 15 Valencia CL-Rd of 16 15 6 1
Feb 20 Gladbach BL 13 7 2
Feb 26 Nurnberg BL 17 5 1
March 2 Bayern Munich Pokal 12 7 0
March 5 VfB Stuttgart BL 22 5 1 (pen)
March 9 Valencia CL-Rd of 16 12 4 1
March 12 Eintracht Frankfurt BL 8 5 1
March 20 Bayer Leverkusen BL 13 7 2
2010-2012 TOTALS 481 175 40

 

Immediately jumping off the page is the Feb. 4 match vs. league leaders Dortmund, where Neuer faced 20 shots (8 of them on target) and stopped every one. 

On the year, that’s 40 goals allowed out of 175 shots on target, for a save percentage of 77.1%.  If you consider all shots faced (not just shots on goal), Schalke’s opponents hit the back of the net on just 40 out of 481 total shots this year, meaning they failed to score on about 91.7% of all shots they took.

Neuer has refused to concede a single goal on 14 occasions this year (out of 38 matches played), giving him a clean-sheet percentage of about 36.8%

HUGO LLORIS

Just for the hell of it, let’s also take a look at Hugo Lloris, who was said to be a target of ours in late 2010.  This includes only games Lloris has played (twice, Lyon has gone with their back-up):

 

Date Opp Comp Shots faced SOG faced Goals allowed
Aug 7 Monaco Ligue 1 9 4 0
Aug 15 Caen Ligue 1 12 7 3
Aug 21 Brest Ligue 1 18 3 0
Aug 28 Lorient Ligue 1 15 7 2 (1 pen)
Sept 11 Valenciennes Ligue 1 11 5 1
Sept 14 Schalke CL-Group 5 2 0
Sept 19 Bordeaux Ligue 1 19 5 2
Sept 25 St. Etienne Ligue 1 5 2 1
Sept 29 Hapoel Tel Aviv CL-Group 9 7 1 (pen)
Oct 2 Nancy Lorraine Ligue 1 19 6 2
Oct 17 Lille Ligue 1 20 9 1
Oct 20 Benfica CL-Group 7 0 0
Oct 24 Arles Ligue 1 8 2 1
Oct 30 Sochaux Ligue 1 7 4 1
Nov 2 Benfica CL-Group 13 6 4
Nov 6 Stade Rennes Ligue 1 10 5 1
Nov 14 Nice Ligue 1 1 0 0
Nov 21 Lens Ligue 1 3 1 1
Nov 24 Schalke CL-Group 13 7 3
Nov 28 PSG Ligue 1 11 4 2 (1 pen)
Dec 4 Montpellier Ligue 1 17 6 1
Dec 7 Hapoel Tel Aviv CL-Group 12 8 2
Dec 12 Toulouse Ligue 1 8 4 0
Dec 19 Marseille Ligue 1 13 3 1
Dec 22 Auxerre Ligue 1 10 4 1
Jan 8 Caen Coupe 4 2 0
Jan 15 Lorient Ligue 1 8 2 0
Jan 23 Nice Coupe 14 5 1
Jan 29 Valenciennes Ligue 1 17 3 2
Feb 6 Bordeaux Ligue 1 10 1 0
Feb 12 St. Etienne Ligue 1 17 7 1
Feb 22 Real Madrid CL-Rd of 16 9 3 1
Feb 27 Lille Ligue 1 12 3 1
March 6 Arles Ligue 1 6 0 0
March 12 Sochaux Ligue 1 7 2 0
March 16 Real Madrid CL-Rd of 16 20 10 0
March 19 Stade Rennes Ligue 1 3 1 1
2011-2012 TOTALS 402 150 38

 

Lloris has played in 37 matches this year, permitting 38 goals out of 150 shots on goal faced.  This gives him a save percentage of about 74.6%. 

Considering all shots faced, Lyon’s opponents have attempted 402 shots on Lloris and hit the back of the net 38 times, meaning about 90.5% of the times they shoot, they fail to score, whether saved or just off-target.

Lloris has completely blanked the opposition 12 times, giving him a clean-sheet ratio of about 32.4%.

When we compare the group, they look like this:

 

KEEPER SAVE % - SOG SAVE % - ALL SHUTOUT %
Kraft 71.6 89.6 31.2
Neuer 77.1 91.7 36.8
Lloris 74.6 90.5 32.4

 

Note that these terms aren’t precise - the percentage of times the offense fails to score with any shot is not properly called the “save” percentage, because some of these fly high or wide and needn’t be saved.  But you get the idea. 

I was surprised at how consistent the numbers are.  For each category - shots on goal saved, total shots kept out, and clean-sheet percentage - Neuer is the best, Lloris is right in the middle, and Kraft brings up the rear.  Of course, there could be numerous reasons for this - you could say Kraft hasn’t had enough time to get his legs under him, he might get better with more matches, etc.  But it’s also just as possible that Kraft might prove worse over more games.  We have to work with the numbers we have. 

You could say that Bayern’s defenders have played poorly, contributing to Kraft’s lower numbers.  But neither Schalke nor Lyon has world-class defenders.  Schalke’s back line has been shuffled all year, and they’ve played the past few months with a couple of 22-year old no-names in front of Neuer.

Then, you have to ask: how big are these numerical differences?  In a sense, not very big (5 and a half percent between Neuer and Kraft on on-target save %) … but over a long season, that makes a big difference.  If a keeper faces about 180 shots on target over a course of a season, the difference between a pretty decent B or B+ level keeper and a truly world-class A level keeper might mean anywhere from 6 to 12 goals prevented.

This year, in all competitions, Bayern has had 16 games end in a loss or a draw.  Of the 10 losses, 5 have been by a single goal, and of the 6 draws, we gave up at least a goal in 3.  This means that, between scoring draws and 1-goal losses, there have been 8 matches in all competitions in which Bayern would have moved on/picked up more points if we had kept one more shot out of the net.  Obviously, not all of our hypothetical A-level keeper’s additional saves would have come in these matches, but it’s a good bet that at least 2 of them would have, and possibly 3 or 4. 

In other words, in the context of our current season, the difference between a B+ keeper and an A keeper would render us still alive in the Pokal, or still alive in the Champions League, or currently in third place rather than fourth in the Bundeliga, or some combination of all of the above.  Which brings us to the sobering conclusion: this is one of the curses of supporting a truly world-class club with a rich history and high expectations like Bayern.  Most clubs can afford to say “hey, current player X came up through our system, he’s young, he’s a hard-worker.  Why should we spend more money and go outside our system just to get player Y who’s only a little better?” 

Bayern doesn’t have that luxury.  Our goal is to challenge for silverware every single year - if not win each competition, then at least be one of the top 2 or 3 teams fighting for the Bundesliga and one of the last 4 teams contending for the Champions League title.  Unfortunately, this means you can’t stick with a solid, respectable home-grown option.  Teams that want to be considered the best in Europe have to upgrade where possible, especially when you have a chance to get a best-in-the-world option at that position.

Thomas - you’re a good kid.  I like watching you play.  I hope you go to a good team and have a successful career.  Right now, you’re a B to B+ player at a position where we need an A.

Sorry to make you guys sit through all the numbers.  Thanks for reading.