For many years Total Shots Ratio has plodded along as a good indicator of team shooting performance, not overall team performance, but shooting performance.
It’s a good enough indicator that its found its way into generic match reports for professional soccer teams and has good visibility on Opta – a well recognized soccer statistics company now owned by Perform Group.
But with all that publicity and ‘useability’ that doesn’t make it ‘right’!
Why do I say that?
Within a game of football there are always two teams playing against each other – so team performance statistics should not only take into account what the attacking team is doing – they should also take into account what the opponent is doing to the attacking team.
So what do I mean about modernizing TSR. Most define TSR has simply the volume of shots one team takes versus the volume of shots another team takes. That’s okay but the end state is excluded – the result – a goal scored.
So my new vision of TSR centers around the end state as well as the volume – in other words the equation for Attacking TSR (ATSR) now becomes Goals Scored/Shots Taken and then Defending TSR (DTSR) becomes the percentage of your opponent’s Goals Scored/Shots Taken.
Finally, in looking at how well Composite Possession with Purpose correlates to Points Earned in the League Table I would create Composite TSR (CTSR).
Before getting to the numbers – some history first:
I built Possession with Purpose using this philosophy and if you’ve been following my efforts for the last two years you know that my correlations to points earned in the league table are extremely high… To date:
- MLS 2014 = .86
- Bundesliga = .92
- English Premier League =.92
- La Liga =.91
- UEFA Champions League =.87
So let’s peel back the regular way TSR correlates to Points earned in last year’s MLS – when viewing the old way (Total Shots only as a percentage for both teams) the Correlation Coefficient “r” for the entire league was .32.
My new way of calculating CTSR with the End State of Goals scored has a correlation coefficient “r” of .75
Far higher… now for some data.
Here’s the correlation of the my new TSR Family of Indices shows with respect to Points Earned in the League Table – the same analyses used with respect to CPWP above:
- MLS 2014 ATSR .74) DTSR (-.54) CTSR (.75)
- Bundesliga ATSR (.53) DTSR (-.41) CTSR (.68)
- EPL ATSR (.86) DTSR (-.35) CTSR (.76)
- La Liga ATSR (.88) DTSR (-.77) CTSR (.92)
- UEFA ATSR (.64) DTSR (-.40) CTSR (.65)
Like CPWP the correlations vary – in four of five competitions the CTSR has a better correlation to points earned in the league table – while in one case (the EPL) ATSR has the best correlation.
So how do the numbers stack up for some individual teams when evaluating ATSR, DTSR, CTSR, and CPWP compared to those teams points earned throughout the season?
In other words what do the correlations look like (game to game) through the course of a season for sample teams within each of those Leagues?
In almost every sample TSR (now ATSR) has a lower, overall correlation to a teams’ points earned in the League Table than CTSR (Borussia Dortmund and Barcelona being the exception) – this pattern follows the same pattern seen with CPWP almost always having a higher correlation than APWP and Goal Differential almost always having a higher correlation than Goals Scored.
I’ve also taken the liberty of highlighting which Composite Index has the best correlation to points earned between all four categories – in every instance either CTSR or CPWP is higher than TSR. But, as can be seen, sometimes CTSR is higher than CPWP…
What this proves is that there simply isn’t one Index that is far better or far worse than the other – it shows that different teams show different styles that yield better relationships to points earned in different ways —> meaning there is not only room for improvement in current TSR statistics but room for the inclusion of PWP principles within the Industry standard.
I would offer – however – that even when you create CTSR the backbone of that data can’t offer up supporting analyses on how a team attacks or defends. It’s still only relevant to the volume of shots taken and goals scored.
And while the volume of shots on goal and goals scored appears to be a constant across most competitive leagues (average greater than 5 and 2 respectively for teams winning on a regular basis) the average of shots taken for winning teams is not as constant… (Expected Wins 4) —> why I favor PWP over TSR – nothing personal – just my view…
I’m not sure I did a good job of comparing what I view as the old way to calculate TSR (the way that ignores the End State of Scoring a goal) and how an update to it can help tell a better story that actually correlates better to the complexities of soccer.
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My thanks to everyone who has supported my web site the last four years!
It’s been a learning experience for me and, I hope, for you too.
As the new year starts I’ve got at least five new articles planned; here’s a quick synopsis on what to expect:
- Following up on Coaching Youth Soccer Part I and Coaching Youth Soccer Part II, I’ll be offering Coaching Youth Soccer Part III – digging into which team statistics to use, why, when, and how to use them. For those who don’t know me these three articles highlight my coaching philosophy into one three word catchphrase “muscle memory mentality“.
- Two new individual soccer statistics: This (may?) be controversial – My intent is to submit two new, professional level, individual, soccer statistics that could transform the player market value system.
Said differently; are private statistics companies, like Prozone Sports, OPTA, and InStat (along with player agents) manipulating the player market value system by ignoring what might be the most logical, intuitive, individual soccer statistics ever?
- Expected Points – An updated version of my previously created Expected Wins series of articles. A follow on to what was offered at the World Conference on Science & Soccer 2017, Rennes, France.
- Expected Goals – A new way to calculate this over-hyped soccer statistic that brings it a bit closer to reality.
- World Cup 2018 Total Soccer Index; to include predicting the winners after round one is complete.
For now, in case you missed one or two, here’s my rundown on the top five articles in each of the last four years.
- World Conference on Science & Soccer 2014 – a power point presentation of what I offered as a guest speaker at this prestigious event. #2 All Time.
- Is European Football Really Higher Quality than Major League Soccer – a look at possession with purpose across Europe as compared to MLS. #5 All Time.
- On Fire – or Can’t Hold a Candle – Are Chicago Fire Burning at Both Ends – a look at Chicago Fire in 2014 and their woes in not winning.
- Possession with Purpose Revised Introduction – my second update to PWP; the most accurate, publicly generated soccer index. #1 All Time.
- Major League Soccer – Week 25 – Portland Finally Show Up
- Possession with Purpose Revised Introduction – two years running in the top five.
- Busting the Myth of Moneyball in Soccer Statistics – my take on the flawed reasoning that individual statistics actually add great value in evaluating player effectiveness. #6 All Time.
- Redefining and Modernizing total Shots Ratio – Debunking TSR – note this statistic has now been shoved to the side. #8 All Time.
- World Conference on Science & Soccer 2014 – two years running in the top five.
- Is European Football Really Higher Quality than Major League Soccer – two years running in the top five.
- US Soccer – Improving College Soccer in the United States – peeling back issues with College Soccer – a topic with a very high visibility rate now. #4 All Time.
- Moneyball 2 – Soccer Statistics Taking it to the Next Level – thoughts and ideas about the next iteration of individual soccer statistics. #7 All Time.
- Training Soccer in America – God Smackingly Obvious Or is It – my first article highlighting my frustrations with US Soccer Youth Development – a topic with a very high visibility rate now.
- Busting the Myth of Moneyball in Soccer Statistics – two years running in the top five.
- Possession with Purpose Revised Introduction – three years running in the top five.
- Porter Pulls out of Portland – Caleb Porter resigns. #3 All Time.
- Updated Possession with Purpose – four years running. Update includes a revision to my Total Soccer Index. Two new algorithmic revisions have the correlation (r) to points earned in the league table exceeding ‘goal differential’; the benchmark statistic of modern day soccer.
- Getting Hot in Portland – On a poor run, Portland Timbers head coach, Caleb Porter publicly humiliates some of his players during post game press conferences – the first article in America projecting he may be out by the end of the season.
- Portland Timbers hire Gio Savarese – Caleb Porter’s replacement; no frills from an MLS shill here – let’s wait till the end of year 1 before drawing any conclusions or over-hyping what he offers.
- It’s not just US Soccer that Needs to Wipe the Slate Clean – The first article offered in the US Soccer media environment that publicly slams mainstream soccer media for inadequate journalism – a topic with a very high visibility rate now.
- I called for Jurgen Klinsmann to be sacked after WC 2014 because his tactics and in-game adjustments weren’t up to snuff. Three years later the rest of the american mainstream soccer media world agreed and Klinsmann was sacked.
- I called for Sunil Gulati to be ‘ousted’ after WC 2014 because his leadership in helping youth development and head coach selection weren’t up to snuff. Three years later the rest of the american mainstream soccer media world agreed and Gulati is out.
- In hindsight – I wonder where we’d be in youth soccer development if we’d have made those decisions three years ago?
- No, I do not favor Caleb Porter as the next US Men’s National Team head coach. I like Caleb, he’s a stand-up guy and always took time to share and listen. That said, in my opinion, he’s not (consistently) good enough at reading in game situations and making tactical adjustments that lead to better performances; the exact same issue I had with Jurgen Klinsmann. .
- I’m hopeful either Eric Wynalda or Steve Gans are elected as the next United States Soccer Federation President; electing Kathy Carter is a NO-GO in my view as there’s perceived ‘collusion’ between MLS and SUM. As a retired Air-Force veteran perception is reality until proven otherwise – some may disagree?
I wish you all the best for the new year.
I’ve been a bit busy lately so apologies for not offering up any research on Possession with Purpose; lots going on with it at the moment while all five competitions I measure are still going at full speed.
To catch up, using a picture first, here’s a look at how PWP compares to Total Shots Ratio as well as Goal Differential when viewing the UEFA Champions League:
As an added Index I’ve also included the PWP Predictability Index (an Index that EXCLUDES goals scored (for or against) in the overall calculations. A reminder that from a pure predictability standpoint the Predictability Index remains the only Index that excludes goals scored when developing a prediction as to whether a team might earn points.
For the benefit of all I’ve also included how things take shape when teams play at home versus away from home; there are differences.
So what does this mean?
PWP, even in a format different than general league play shows better than TSR as it is known today (i.e not modernized).
While Goal Differential shows well with respect to the overall correlation coefficient (r) to average points earned it doesn’t show best when racking and stacking it as an Index compared to PWP —> when viewing how it ranks teams versus how well they have progressed into the final stages.
What I found intriguing was that the PWP Predictability Index (which excludes goals scored) actually racked and stacked the top 4 teams in the UEFA Champions League better than Goal Differential.
If you’re someone who likes to bet on games early indications show PWP Predictability (excluding goals scored) has FC Bayern ahead of Barcelona and Real Madrid ahead of Juventus.
Of course Arjen Robben has been injured, and given his considerable influence with FC Bayern Munich that predictability model pretty much goes out the door – or does it?
I’d say yes, because when adding goals scored (the PWP Index) Barcelona leap-frogs past FC Bayern; meaning it is highly likely we see Real Madrid and Barcelona in the Finals…. but you decide.
Awhile ago I wrote that FIFA needed to change how they rank teams across the World.
I remain stubbornly steadfast and steadfastly stubborn that the outputs from both the UEFA Champions League and World Cup PWP Indices lend credibility to the suggestion that FIFA revisit protocols on how they seed teams in their various competitions.