Men have trouble scoring

Did the number of goals decline in the men's Olympics?

Introduction

Shane McLeod, in his usual calm, thoughtful review of the Belgium performance at the Olympics during an AMA on the Hockey Site last week, mentioned that fewer goals had been scored during the tournament than the last few major competitions. He gave a reason too. Fear of the aerial. Teams had organised themselves lower on the pitch, became more defensive, in the face of the threat posed by the aerial into the circle.

This, I thought, is eminently testable - was the last Olympics a lower scoring tournament than previous tournaments?

Data

If we take the major competitions since and including the last Olympic Games we get the World Cup (2023), ProLeagues (2021-22, 2022-23 and the most recent 2023-24), the last European Cup (2023)¹ and of course these recent Olympic Games. That’s 356 games and 1776 goals at an average rate of 4.9 goals a game. And that’s pretty much all we need in terms of data to confirm Shane McLeod’s comment.

Analysis

I think we’d expect some variation across these seven tournaments but the first thing to do would be to compare them all.

This analysis says there is an overall difference between tournaments (p = 0.04) and that the number of goals scored in the last Olympics was significantly lower than the last World Cup. Support for the idea that there were fewer goals, but not very strong support. We might strengthen the analysis by pooling all the other tournaments together (which we can do as none are different from each other) and then compare them to the last Olympics.

Now the effect is strong. The 2024 Olympics was a lower scoring tournament than the last six major tournaments combined.

Is there a trend? I mean, if the threat of the aerial ball has been increasing it might be reasonable to think that there should be a concomitant decline in the number of goals scored over the recent years represented by these tournaments. Is there?

Well, yes there is. The number of goals scored shows a negative relationship with time - again not that strong an effect, but still a significant one (p = 0.04). The World Cup had an exceptionally high number of goals per game (average = 5.7). But the next two tournaments (Eurohockey 2023 and ProLeague 2023-24) both had lower average scoring rates than the previous tournaments (4.8 and 4.7 goals per game respectively). Perhaps the defensive response to the aerial carnage of the World Cup is already evident in tournaments since and the low scoring of the 2024 Olympics is just the continuation of this trend.

Alternative corroboration

It’s possible to do a lot more with this data as we could look at the teams, goal timing, match types etc, etc in terms of goals scoring. But an alternative way of testing the conjecture is to look at the women’s game. Sure the women are throwing more and longer aerials. And more are being aimed at the circle. But I think it a reasonable guess that this in no way matches the frequency nor distance aerials are thrown in the men’s game. So, a priori, one might expect there to be no impact of the aerial ball on the organisation of the defence in the women’s game and hence, no change in the number of goals that were scored in this Olympics compared to the same range of tournaments we’ve just looked at in the men’s game.

And here is the answer.

There is no difference, not even the slightest hint of a difference in the number of goals scored between the tournaments in the women’s game (p = 0.92). If we simplify the comparison, as we did above for the men, we get this.

Which again shows very clearly that there has been no change over the last few years. And the trend?

There is none. One couldn’t really get a flatter line. Goals scored in the women’s game have been going in at a similar rate since the 2020 Olympics.

Conclusions

The men’s game did see a decline in the number of goals scored in the last Olympics and a trend in tournaments since the World Cup to fewer goals per game. But, it is important to note that the results do not demonstrate that the lower scoring is caused by the change in defending tactics because of the threat of the aerial ball - that would be going too far. No, the results simply confirm the observation by Shane McLeod. To determine whether there was a causative effect of attacking aerials on deep defending and lower goal counts we should start collecting data on the frequency and spatial distribution of the aerials thrown across these tournaments. We should, if we have time to do that, which I don’t. So I have to leave it there². And if Shane McLeod thinks attacking aerials are the cause then, in the absence of any more data, it would be reasonable to agree with a coach of his caliber and first hand experience of the tournament.

Shane McLeod also speculated on the remedy for this decline in goals. He is of the opinion - as everyone seems to be - that more goals are better and their decline in the last Olympics, and the purported cause, needs some remedy. His suggestion was to restrict where an aerial can be thrown to outside the stipple line, the dotted line mimicking the circle and five metres further away. Fair enough, that sounds like a reasonable suggestion. And it is the case that rule changes in the last thirty years have increased the appeal of the game - more goals are being scored now than at any time previously.  But not evenly - men’s scoring rates have increased faster than women’s (see here).

Accordingly, because rule changes act holistically across the game, any change suggested to counter the increasingly defensive nature of the men’s game should also take into account whether it is actually needed in the women’s game. According to the analysis above it isn’t. Indeed it may even stymie the development of a more attacking approach by the women. So I do wonder how much thought goes into assessing up front, how rule changes, prompted by the concerns of one discipline as here, may differentially impact both game disciplines when implemented. Naturally, the only robust way to find out is to do the appropriate analysis.

1. The eagle-eyed among you will have noted the ‘deliberate’ error. I somehow missed the EuroHockey 2021 tournament that falls in the timespan of this dataset. It won’t change the results, goal scoring was high in that tournament.

2. But if anyone has that data, I’m happy to have a look……….