GAA football - historical trends

I have been amazed at some of the hurling scorelines in the last 12-24 months, with teams regularly posting 25+ points per game, and I have a vague memory of hearing that Limerick had 55 shots on goal in one particular game.

I was interested to see what the evolution of scoring in football looks like, so I had a delve into the data.

First of all, I pulled out total scores per game. The graph below shows the average score per game per year since 1926 (I chose years where there were at least 25 games across league and championship for the results to be meaningful). The blue line is the smoothed average scores with the shaded area the standard error, while the black line is the actual average score.

My first impression after looking at this was to say that yes, clearly the total score has been increasing since 1926, but that there were some peaks and troughs that looked quite strange. To go further, I broke it down to average goals and average points per game.........

This really helps to shed more light on the evolution, as it seems that there has been an almost linear increase in average points per game scored per year (with a stagnation during the '80s until something caused a spike in 1990).

The average goals scored looks more complicated to explain - there seemed to be a trend towards an increase up to the late 1940s, and since then, average goals per game declined, reaching a minima of 1.5 goals per game in 1995. There was a major outlier in 1990 with 2.9 goals per game being scored. There seemed to be a lull after 1995 until recently - over the last 8 years, there has been an average of 2 goals or more per game.

I'm having difficulty to understand what might have driven these changes. I thought of the 80 minute championship games which was in place from 1970 - 1975 (previous to this, championship games lasted 60 minutes) but this doesn't look like it had a huge effect). Another factor that might have an overall affect is that extra-time was not a thing in the days of old (I don't even know when extra-time came in).

Anyone got any insights?

No, I don't have the data on scores from play vs from frees and it would be interesting to look at this aspect. I would wonder if there are more frees now compared to 30-40 years ago. Or even to earlier days - in the recesses of my memory, I remember that a Laois man held the record for quite a long period of time for top scorer in a Leinster final - 8 points, all from frees.

If there was, I don't remember.....One thing that might have had an effect were the years where they scrapped the divisions in the league and had 4 groups of relatively equal strength. I remember Kilkenny getting some right hammerings at the time. I will split out the above into league and championship when I get some time over the weekend.

So I split the data into league and championship.........

Relatively little difference between league and championship in terms of goals scored, except for 1977 and 1978 where there was a huge spike in goals scored. Hard to understand what drove this, but 1977 will be remembered for 8 goals being scored in the Dublin-Armagh final, and the first round of the 1978 championship also delivered 8 goals (Carlow 5-08 Westmeath 3-09). Carlow leaked 6 goals to Dublin in the following round and scored 2 themselves. The spike in goals scored in 1990 could possibly be explained by the increased time the ball was in play as mentioned by @TCDStudent1 and @WesternZulu above, with teams quickly correcting this exuberance in the following years.

In terms of points, the drier ball is surely the explanation for the difference between SFC and NFL over the years. Results from 2021 showed little difference between league and championship - time will tell if this is a trend or a once-off, possibly due to more open games during the Covid-induced empty stadiums.

The increase in number of points during the 80-minute trial (1970-1975) is evident, and this higher scoring rate appears to have remained for a few years before dying back in the '80s. There is definitely an increase in the number of points scored from the early 1990s. This could also be explained by the additional time the ball was in play, which likely manifested as extra goals in the first year, followed by a greater focus on avoiding conceding goals at the expense of conceding additional points.

I had to cut this one as there were about 50 games where the losing side had scored 4 goals. As shown in the graphs in previous posts, goals appeared easier to come by in the earlier days of GAA.

This table needs to be read in the context that in some of these games, the game went to extra time, so the loser had longer to build up a score.

Idem for this table, if the game went to extra time, the loser had longer to build up a score. Interesting that only 2 of the games came before 2014!