Okay, here we go:
Comparing between different eras is difficult. Many in here argued that Cristiano’s goal record is far superior to R9’s, even during his prime. And while this is factually true, those who prefer the Brazilian’s peak argued that you cannot compare these numbers due to the goal inflation that took place in La Liga as well as an incredible goal deflation that happened in the Serie A dring the 90s. A certain user also argued that it was unfair to compare Cristiano’s long lasting peak with Ronaldo’s short flash of genius. So what I’ll do is, I’ll consider prime R9 (94-98) and compare him to prime Cristiano and try to factor in the differences in goals scored by top teams by computing an expected goals value for top teams of each league in the respective time frame.
Since this comparison will be only about goal scoring, we’ll take the four year period in which Cristiano had the best minutes per goal ratio. This will not about “what-ifs” or possible future scenarios or something like that – just what the players actually did. I chose minutes per goal as a metric since it perfectly depicts the goal threat a player depicts when he’s actually on the pitch. Peak instead of longevity since it is no discussion who wins in the latter. So, what was CR7’s best time, then?
This is in fact the period from 11/12 to 14/15 during which he scored every 82.7 minutes across all competitions. Worth mentioning, however, that you could also take 12 – 16 (83.4 minutes), 13-17 (83.4 minutes), 10-14 (85.8 minutes) or 14-18 (84.5 minutes) which is a testament to CR’s consistency.
Pre-injury Ronaldo averaged a goal every 97.30 minutes in the period from 94 to 98. However, it is worth mentioning that his numbers went downhill enormously when he joined Inter and the Serie A. Before his move to Italy, Ronaldo had scored every 88.79 minutes, yet in Serie A this ratio dropped to a goal every 122 minutes.
This can be explained with the competitiveness and defensive prowess of the Serie A in the 90s. In 97/98, the three teams with the most scored goals in Italy were Juve (67), Rome (67) and Florenz (65) – that’s an average of 66 goals. To provide some context, in 96/97, the top 3 were even worse with Sampdoria (60), Lazio (54) and Juventus (51). Juve managed to win the Serie A with 51 goals. In the following season, top teams performed slightly better with Roma (69), Lazio (65) and Milan/Inter (both 59) being the teams with the most goals. If we factor in these results in order to get a bigger sample, the average goal expectation for an (offensive) top team of Serie A was at 61,6.
In contrast, Real Madrid scored 121, 103, 104 and 118 goals in the considered time period from 2011 to 2015 (111,5 goals on average). The one comparable team in the league, Barcelona, scored 114, 115, 100 and 110 goals in the same time frame (109,75 goals on average). This means, as a top team in La Liga you were expected to roughly score 79,5% (!) more goals than a top team in Serie A during R9’s prime.
Using the same “model” on the La Liga seasons 95/96, 96/97 and 97/98, we get a goal expectation value of 79,4. Worth mentioning at this point that the only time a team scored more than 100 goals in that sample was when Ronaldo played for Barcelona. In general, you can say that La Liga top teams in CR7’s time are expected to score 39% more goals than in R9’s time. At this point, some may ask why I chose to use the average of the three best teams in R9’s period but only the two best in CR7’s. This is because in the 90s, the differences weren’t that clear. Madrid and Barca regularly ended up outside of the top 3 and their goals scored and total points were a lot closer to the rest of the bunch. During Cristiano’s time in Spain, the difference between Barca and Real on the one side and every other team in terms of offensive prowess is so gigantic that it wouldn’t make sense to factor in more than these two squads.
Some will now argue that this is actually because of the “Cristiano/Messi effect”. Arguably, their teams reached those crazy numbers solely because these two players played for them. In order to judge this, we can take a look at Cristiano’s and Ronaldo’s share of team goals. From 2011/12 to 2014/15, Cristiano contributed 33,9% of Real Madrid’s. Ronaldo from 94/95 to 97/98 contributed 30,63%. However, he missed half a season of football back then since he only played 1365 minutes in 95/96 (during which he still managed to contribute roughly 15% of PSV’s goal output of the whole season). If you take this season out of the equation, you reach an average contribution of 36.77%. For the Inter squad of 97/98, he even contributed 40% of their total goals. That’s slightly better than Cristiano’s best result of roughly 38% for Madrid in 14/15. Since these stats indicate that CR’s and R9’s importance for their teams is almost identical in terms of goal scoring, this argument can therefore be neglected. If anything, R9’s is slightly ahead.
So, how can we interpret these numbers?
Now, if one considers the goal inflation effect as well as the goal deflation in Serie A and adjust Ronaldo’s goal records accordingly, he ends up with 77.93 minutes per goal in the period from 94-98 which would be better than Cristiano's. This stat should of course be considered with a grain of salt but it highlights how ridiculously good Ronaldo’s goal scoring numbers were at a time when top teams scored far less goals than today – far better than interpreting his record in modern context suggests.
However, this quick analysis obviously still has many weaknesses. For one, it is true that Cristiano’s and Messi’s goal record is far ahead of anyone else in their time (didn’t have the motivation to do a similar comparison between R9 and other strikers of his era) and their peers struggled to put up comparable numbers even for a single season.
However, on the other hand Messi and CR7 were the centers of arguably the two best teams in the world which additionally played in a league in which they were several levels above everyone not named Atletico (which was only one level below them) - that was never true in the same way for R9. At the very least Suarez’ goal record in his best Barca season, Salah’s for Liverpool in 2017/18 or Mbappe’s and Neymar’s currently for PSG shows that other players can come close to it if they are the main target in a team that can dominate other teams through overarching quality. Apart from that, only R9's league goals in Spain and Italy have been adjusted to the expected goal values. If you wanted to be completely precise, you'd also had to consider factors for CL campaigns and other competitions which could possibly tilt the balance in favour of Cristiano again.
Additionally, minutes per goal in general does not factor in that Cristiano’s resistance to injuries is definitely worth considering. Even if his “goal density” does not beat Ronaldo’s you can still say that his consistency allows him to be on the pitch for more minutes throughout a season and thus score more goals. Yet, the Brazilian also never really played for a team as streamlined and “grown” as CR7’s Real Madrid. Instead, Ronaldo in his prime never spent more than one or two years at the same club, scoring insane amounts of goals from the very first day without any need for settling or adjusting. Nobody can really say how he would have profited from the automatisms and mutual understanding which teams profit from that grew together throughout multiple years.
Anyway, in general I think that R9's goal output if interpreted with the respective circumstances and context of his time in mind are much more impressive than at the first glance.
