So, Harry called time on his QPR tenure last week leaving behind a trail of stats which, at first glance, make for miserable reading; an 18.75 win percentage in the Premier League looks even more gloomy when you consider the 20 win % of Mark Hughes and Neil Warnock. However, such a stat, along with the league table, only tells part of the story. By its nature, football is a game of very few significant events / goals, therefore looking at the scoreline alone can be unreliable as a method for differentiating between teams. If you’re not convinced by this statement, just think back to a game when you thought your team didn’t deserve to lose, or were robbed a winner by a wrongful offside call.
With this in mind, I thought I’d take a look at some stats to see exactly how bad QPR have been this season, and in particular, a few fancy stats that you won’t have seen discussed on Sky Sports yet, but are widely accepted in the sports analytics community.
Total Shot Rate (TSR)
This is simply the ratio of shots taken and total shots (Shots For / Total Shots). Anything above 50% means a team has taken more shots than they have allowed against them, and typical values range from 38-62%.
TSR is a good indicator for team strength as, since the 2009/10 season, 3 of the last 5 titles winners have recorded the best ratios while 7 of the worst 15 recorded were relegated.
At this point I will add that all stats are quoted from the excellent www.objective-football.blogspot.com (@ObjectiveFooty), unless otherwise stated, and include up to and including game 23 so that we can look back and compare Harry Redknapp’s team with his successors.
QPR: TSR = 48.4% (Rank = 12th best in Premier League)
Shot on Target Rate (SoTR)
Very similar to TSR, SoTR considers only those shots on target (SoT For / Total SoT). Again, typical values range from 38-62% and correlate nicely to the strength of a team. 15 of the top 20 rates posted since 2009/10 have been from title winners or Champions League qualifiers, while 11 of the worst 20 have been relegated.
QPR: SoTR = 41.9% (Rank = 14th best – the rank flatters here as such a SoTR falls within the bottom 15% recorded since 2009).
You read right, you can begin to measure luck with a stat called PDO, which is the sum of scoring percentage and save percentage. PDO is considered a good indicator for luck as it regresses towards its average of 100 with time, and about a typical range of 90-110. (You can read more about PDO here).
QPR: Scoring = 25.8% (Rank = 18th, with a league average of 32%)
QPR: Save = 67.4% (Rank = 12th, with a league average of 68%)
QPR: PDO = 92.9 (Rank = 16th luckiest)
There are a few other stats of note which I will cover in a future post, but you might be looking at the indicators above wondering why QPR sit in 19th position in the league. The answer is score effects which account for some inflated values in QPR’s case. Score effects (or game states) are simply the goal difference at any point during a game. You can read more about these effects here, but to summarise, approximately 86% of game time is spent at what are known as the close game states – those which are tied or where a team is either trailing or leading by 1 goal.
Why is this significant? Well, teams trailing by one goal out-shoot those who lead by one goal. They also have a greater share of shots on target, but their accuracy goes down, scoring fewer of the goals. Here’s how QPR have performed at the close game states, compared to the league averages for those game states:
And here’s the score adjusted figures for QPR (hard graft to remove the score effects bias by @ObjectiveFooty):
TSR = 46.9% (Rank = 13th)
SoTR = 41.1% (Rank = 14.5th)
Score % = 25.8% (Rank = 19th)
Save % = 68.5% (Rank = 7th)
Luck = 94.2% (Rank = 14th)
So, there’s hope, no?
The league table doesn’t lie and makes for some grim reading right now, particularly the away form. Being the optimist, I’m buoyed by the figures posted. I don’t think we are as bad as the league table suggests. Our PDO (luck) is low, driven by a horrific score % and I’m hoping we benefit from a regression to the mean soon. Also, our SoTR needs to improve which is in the bottom 15% for the last 5 seasons. This can be improved with better shot choices which I will cover in a separate post.
Most concerning, and what is really driving our league position, is our general performance when games are tied. We spend 46% of our time tied but this is when we are at our worst. We don’t seem to wake up and play until we go a goal behind, which is when we start to look like an average Premier League team. I’ve convinced myself that we are not one of the worst three teams in the league, and I’m looking forward to comparing these numbers with those of Harry’s successor. If we do manage to survive, no doubt the new manager will take all the plaudits, although I’ll be keeping an eye on that score percentage (and PDO) before dishing out too much praise.
Just to finish with Sunderland ahead of tomorrow’s game, here’s how they compare:
Sunderland are producing some bad figures. At first glance they appear to be doing alright at the tied and -1 game states but this is all driven by their PDO, and in particular Pantilimon, who surely cant keep up such a save %. Across all close game states their TSR and SoTR is bad, relegation bad. Hopefully, tomorrow we see our score % and their save % regress. And, if we do find ourselves going behind, keep the faith, because their +1 stats are awful.
Here are Sunderland’s score adjusted numbers:
TSR = 38.6% (Rank = 20th)
SoTR = 38.9% (Rank = 18th)
Score % = 30.6% (Rank = 12th)
Save % = 74.9% (Rank = 2nd)
Luck = 105.5% (Rank = 3rd)