Winning Metrics in the PSL

By Alex Rathke

**This post originally appeared on City Press’s Sports pages on June 3rd, 2018. If you missed the issue, we have added the blog piece below. **

Over the past week and a bit, we have been busy! Planning the next couple pieces of content and examining what was possible with our dataset of PSL games (17/18 season). During this time, we came across work done by 21st club and the newly established scouting and coaching courses from CoachTechSoccer. A few months back they teamed up and released visuals entitled “Win percentage when outperforming the opposition in a particular attacking metric”. This got us thinking…would we be able to recreate these visualisations and examine the 2017/18 PSL season gone by? We sure could!

First and foremost, the metrics available were slightly different to the metrics chosen by 21st club and CoachTechSoccer. This was probably due to the different data providers. Nonetheless, the metrics make for easy understanding. How does one win games? By scoring more goals than your opposition. How do you score more goals than the opposition? By creating more shooting opportunities. Yes, but wait. Not all shots are created equally as we already discussed in a previous piece. Shots from outside the box are less likely to hit the target and produce a goal than shots inside the box. Most importantly, in the PSL hitting the target seemed to be the biggest predictor of winning a game against taking a ton of shots. After all, these shots could be of terrible “quality” and fly over and wide of the goal. The next three metrics (Key Passes, counter-attacks and Shots inside the Box) are defined as follows:

1. Key Pass: the final pass or pass-cum-shot leading to the recipient of the ball shooting (regardless of the outcome of the shot) – Opta.
2. Counter-attack: create space for a quick break – in it’s simplest form.
3. Shots inside the Box: includes all shots within the 6 and 18-yard box.

It is interesting that these three metrics all come within 1% of each other and rank that high in the graph. Definitely shooting from inside the box allows for higher quality chances to be created and converted. This would (in principle) agree with the three above metrics, however, there is so much that we have not accounted for (defensive pressure, shot quality and so forth). Elsewhere, could there be an underlying meaning for the type of league the PSL is? Personally, we are not so sure.

Examining the average number of shots taken per game versus the same figures for counter-attacks and key passes, something appears off. The number of key passes (13.05) is higher than the number of shots taken (11.7), which does not add up if we consider the key pass definition above. Unless of course, blocked shots are not counted as part of this figure? In addition, the number of counter-attacks (21.15) are also on the higher end. We do not have any way of comparing this to another league but it would indicate the PSL as a fast and direct league. Whether this is true is something we hope to examine further down the line. For now, err on the side of caution. There are two possibilities to explain this: 1) a slight data collection issue (the provider) or 2) a different understanding of the definitions as we know them (here at Laduma Analytics). We hope it is more so the latter than the former.

Either way, the graph does offer valuable insight for clubs, coaches and football fans alike. In general, hitting a higher number of shots on target than your opponent sets you up to win the game. This is further helped once the chances are taken inside the box and you also out-shoot your opposition. Obviously, we should add that this is not a viable option for all PSL teams to live by. It is rather a guide as to what and how teams can win games.

Comparing Leagues

Using the visuals that 21st club and CoachTechSoccer made publicly available on Twitter, we can compare how the PSL ranks in comparison to other leagues worldwide. There was a fair share of different metrics used by 21st club, while some matched what we had access to. The only metrics we were able to compare for this part were (Shots on Target, Shots inside the box, Shots outside the box, Dribbles attempted and Possession).

Again worth noting that the definitions & data collection methods might be slightly different but nonetheless, we can try and make sense of the graph. The big picture paints the PSL inferior and that is hardly a surprise to many of us. The quality of football is lower but not as bad in some regards. For example, the shooting statistics appear to come down to the quality of finishing (lower % of shots hitting the target). This is absolutely top-level and much deeper analysis should be considered to fully understand the differences. In terms of dribbling, African players like a bit of “magic” and entertaining the crowd. While we cannot see how dribbles directly affect a team winning over another, it is an aspect of moving the ball up the field and creating space for chances to be taken. Possession feeds nicely into a piece that we have previously discussed. The emphasis on possession in terms of winning does not appear to be as important in the PSL as to the Premier League.

In conclusion, each league has a certain strength and with that, some metrics are considered more important than others. Without starting a debate of which league is considered “the best”, the Premier League is known for the most competitive (harder to win the title). Other leagues are known for other areas – Bundesliga (most goals per game – 2.89; based on 8 seasons worth of data) and Serie A for the defensive style of play.

We only had one season worth of PSL data so it is important to note that numerous seasons could have an effect on the graph above. Elsewhere, our next piece will examine the top 5 metrics (Shots on Target, Key Passes, Counter-Attacks, Shots inside the Box & Shots Taken) on a team level across the PSL. Which teams took advantage of these 5 metrics having the “winning” power?

Stay tuned to find out!