The probabilities of reaching the quarter-finals

The first legs of the Machineseeker EHF Champions League play-off round have been played over the past few days. Only once did the home team win (Orlen Wisla Plock defeated HBC Nantes, 28:25), while the visitors prevailed three times — OTP Bank - PICK Szeged lost against Paris Saint-Germain Handball, 30:31, Industria Kielce were beaten 27:33 by Füchse Berlin and Dinamo Bucuresti lost to SC Magdeburg, 26:30.

That is not all that surprising, because in the knockout stages since 2009/10 when the FINAL4 format was introduced, the home team has won just 36.7 per cent of the first legs. The results are also not a good sign for the three losing home teams, because just in 5.3 per cent of cases the home team of the first leg advanced after losing at home. However, these were all either one- or two-goal defeats. No home team that lost in the first leg by more than two goals has ever been able to reach the next round.

How to predict who advances

With that in mind, it seems quite difficult for Kielce and Bucuresti, especially, to turn things around. Szeged appears to have a slightly better chance while Plock against Nantes seems to be the most open play-off tie. These rough estimates, however, can be illustrated somewhat better with the help of statistical models and data from previous seasons.

For this purpose, all data from two-legged knockout stage ties since 2009/10 was taken. The 2019/20 season was not taken into account, as there was no knockout stage due to the Covid-19 pandemic. Matches that were not played and were awarded to one team were also not included, while matches that were decided by the old away goals rule were counted as draw, because today they would be decided by a penalty shootout.

This results in a total of 147 matches with first and second legs. That's not a particularly large sample, but still enough to get some insight. 

In order to derive predictions for the current round, this data was entered into a logistic regression. A logistic regression is a statistical model that is used to predict probabilities for two possible outcomes, in our case whether the respective team will make it to the next round or not. Predictors used were the goal difference from the first leg and the difference in points per game from the group phase as a simple estimate of the teams' general strength.

From 2020/21 onwards, when the current format of the Machineseeker EHF Champions League was introduced, this approach is easily utilised. The same applies to 2014/15 and earlier.

From 2015/16 until 2019/20, however, the group phase included two different types of groups. Groups A and B had one team immediately going into the quarter-finals, while five went into the last 16. Groups C and D together sent just two teams into the last 16. The teams in groups A and B were stronger than those from C and D.

Therefore, the points per game of the teams from the latter groups were divided by 2.2. Thus, their number of points per game roughly resembled those of a team that finished in fifth or sixth place in the first type of groups.

Of course, another way to predict the outcome is to simply ask ChatGPT!

What can be deduced for the current round

The model sees Kielce against Berlin as almost already decided. The six-goal difference and the fact that Füchse were clearly the better team in the group phase gives them a 98.6 per cent chance of progressing. The probability of a penalty shootout is less than 0.1 per cent, while Kielce are still considered to have a 1.4 per cent chance of progressing.

While Magdeburg won by four goals in Bucharest, during the game at times it looked like the German side would win by a higher margin, as they led by eight goals by the middle of the first half. If they had won by that much, the model would have given them a 99.1 per cent chance of advancing to the quarter-finals.

Nevertheless, the model gives them a probability of 95.0 per cent. Dinamo's chances of progressing are at 4.3 per cent and their chances of at least forcing a penalty shootout is at 0.7 per cent.

The calculations are, of course, also based on home advantage. The fact that Magdeburg will not play the second leg in their usual GETEC Arena due to scheduling conflicts but in the smaller and unfamiliar Anhalt-Arena in Dessau could therefore not be taken into account by the model but could become a factor on Wednesday.

Thanks to a buzzer-beater direct free throw goal by Borut Mackovsek, Szeged reduced the deficit to just one goal at the last moment against PSG. This goal alone improved their chances of progressing by 3.4 percentage points.

Nevertheless, the model sees Paris as clear favourites as they go into the home game with the lead and puts the probability of the French side progressing directly at 86.4 per cent. Szeged is only at 11.9 per cent and a shootout at 1.8 per cent.

The model sees Plock against Nantes as the most open game. Although Plock only finished sixth in their group and Nantes finished third, the Polish side won by three goals. However, as the model sees Nantes as the stronger team based on their performance in the group phase and they go into the second leg with home advantage, it believes they are 52.5 per cent likely to turn it around and still progress.

Plock are at 38.8 per cent, still clearly the highest value of all teams who have to play away in the second leg. There is a 9.7 per cent chance that a penalty shootout occurs.

More from data analyst Julian Rux can be found at Handballytics.de. There you can read his latest articles, in which he analyses all kinds of handball topics from new, data-based perspectives. You can also find him on Instagram, Bluesky, Threads and WhatsApp Channels.

Main photo © NM, Feature images © Orlen Wisla Plock, Eliza Solya