Analysis of the Polish Highest Football League Competition System

The paper is focused on analysing the competition system of the highest Polish football league, in particular the championship part after the main competition, introduced in the season 2013/2014 and modified in the season 2017/2018. It is a study of the changes in the rankings after the regular part of the season, both in the group playing for the title and in the relegation group. It simulates a hypothetical situation as if the system had not been changed for the 2017/2018 and 2018/2019 seasons and the situation as if the current system had been played since the 2013/2014 season. In both cases, the results do not show huge variations, which so far challenges the needs for the 2017 modifications. In the term, we can see a trend of higher variation of standings in the championship part after the main competition rather than in the relegation group. However, there are no major variations regarding the last two positions meaning In the six analysed the standings varied only in the 2015/2016 when only one team regarding the relegation in both of championship group two of six analysed season team their positions and became the final champions.


Introduction
Collective sports make use of league competitions. For professional sports, these can be of two types -"closed leagues" and "open leagues" [7]. Closed leagues are typical for North American competitions and their main characteristics is that entering or leaving them for sport-related reasons is not possible. As a result, clubs have to cooperate closely. They make agreements about transfer politics, salary cap levels, revenue sharing methods and other means for preserving financial stability of the participating clubs and the resulting competition balance [13].
Open leagues are typical for Europe and their main characteristic is that it is possible to be relegated from or advanced to a higher league. This system is the main tool to maintain a competition balance of such system. The weakest clubs are relegated and replaced by the best teams from lower-level leagues. There is no typical strategy of mutual support between teams [1].
In European football, the winner and the relegated teams of a league are decided during the season. The way of competing is called competition format and each country elects it by itself. The prevailing form of these competitions is the so-called double round-robin system, when each team plays each team twiceonce at home and once as a visitor [9]. This includes the five most important European leagues -English Premier League, Spanish La Liga, German Bundesliga, Italian Serie A and French Ligue 1. After playing all matches, the league champion, the teams promoted to European cups and the relegated teams are decided. This competition system can be considered as fair, seen from the sports point of view.
Recently, we can see an increase of "play-offs". After the main competition, usually played in the double round-robin system, the teams divide into several groups and continue in smaller competitions. The league organisers mainly expect higher attractiveness of the competition. The teams play more crucial matches, which increases their quality and competitive skills. The after-main competition phases have also an economic effect, generating higher incomes from media rights, tickets, food and merchandising [8].
As for the 2018/2019 season, six countries have made changes to the format of their domestic top-tier competition. The top divisions in Austria and the Czech Republic have changed from a traditional system to a season divided into two parts, with clubs being split into two groups after the main competition [10].
Polish Ekstraklasa league have used the after-main competition part since the 2013/2014 season. They inspired other countries to adopt a similar system. For instance, the Czech Republic, introduced such a system from the 2018/2019 season. Polish experiences can become very useful for the development and the prediction regarding the Czech highest league.
The goal of this research is to identify the influence of the after-main competition introduction on the final results of the Polish Ekstraklasa in 6 seasons (from 2013/2014 till 2018/2019).

Material and Methods of Research
The used data contain the results of the competition after the main competition and the final results, all taken from the website ekstraklasa.org. Comparative analysis has been used, in particular concerning the comparison of the results after the main competition and the final results. Also two model situations have been compared mutually. The first one assumes further existence of the first phase model in the seasons 2017/2018 and 2018/2019. The second one models the situation that there was only the second model (after 2017) system from the begin-ning (season 2013/2014). The results are compared. Mainly the modifications of the positions have been followed and analysed. As crucial modifications, shifts of positions of different teams at the highest positions were concerned, because these mean the acquisition of the championship and the participation at the European competitions; also the positions at the bottom of the table, meaning relegation, have been considered of highest interest for this study.

Ekstraklasa
Polish highest league has been played since 1927 [3]. Excluding the 1946/1947 season, the double round-robin home-away system was used until 2013. The team that reached the highest number of points became the league champion.
Since the 2013/14 season, Ekstraklasa has used a modified system: After the main competition, based on the double round-robin system with 30 matches played by each team, teams are divided into two groups of eight. The first (championship) group plays for the places in the UEFA Champions League and UEFA Europa League. The second (relegation) group plays for remaining and relegation.
Both groups use the round-robin system, each team playing each opponent only once. The four best teams of the group get the advantage of playing four matches at home and three matches away. Altogether, each team will have played 37 matches. The team with the highest final number of points becomes the league champion. The two teams with the lowest number of points are relegated.
Points were an important part of the after-main competition. It began with the points from the main competition, were halved and, if necessary, rounded upwards. Up to Kaliszuk, it was done to increase the attractiveness of the after-main competition and its importance [5].
This system gave advantage to the teams that were successful at the end of the season. Soon both teams and the Polish Football Association (PZPN) began to criticise it. That brought a modification of the system. Since the 2017/2018 season, he division into two groups has remained, but the halving of points from the main competition disappeared. The teams keep the whole amount of points gained during the main competition [5].

Results
The results are divided into two parts, first, the variation in the positions in the championship group, and then in the relegation group. The tables below show both the positions after the main competition and after the after-main competition have been finished. Table 1 shows the official standings at the end of each part of each season. Table 2 shows a model situation as if there was no modification in the system in 2017 and the points were kept divided by two. Table 3 shows the situation as if there has been only the system not transferring all points since 2013. Model situations, thus not following the reality, are in grey.     These variations are important, as the after-main competition decided about the champion in four out of six cases. There were no other important changes in the championship group standings. The first three teams can play in the UEFA competitions. Only once in the six seasons, one team got to such a position from a worse than third place after the main competition. This happened in the 2015/2016 season, when Zaglebie Lubin took profit of this competition part to move from the fourth position to the third one. At all other occasions, the first three teams after the main competition could successfully keep these UEFA places. Table 2 Table 4 shows the standings after the main competition and the relegation group. In this group, the number of points is lower and the post-main competition part has more influence. Therefore, it is not surprising that more variations in standings take place in this group than the championship one.
The largest improvement took place for Piast Gliwice, who jumped in the 2016/2017 season from the 15 th place (relegation) to the 10 th place and "saved" themselves. On the contrary, the largest position worsening was for Podbeskidzie Bielsko-Biała in the season of 2015/2016, as they fell from the 9 th place to the last 16 th position and were relegated. It is interesting that this team was not on the 8 th place, guaranteeing the championship group, only because of a worse goal difference. Table 5 models the results for the case, if the points acquired during the main competition were halved (divided by two) for the whole studied period. Table 6 presents the ranking of the teams for the situation, if the main competition points were not halved for any of the analysed seasons and all acquired points were completely transferred into the after-main competition part. From the presented tables, it is clear that only one team would have suffered from the system with halving the points.

Discussion
The analysis shows interesting facts. The 2013-17 model saw the main competition points divided by two. This was modified from the 2017/18 season by transferring all the main competition points. The main argument was that the worse teams had received an unfair chance to catch up with the better teams in points [5]. The analysis has shown that if the points were not divided by two and the points were kept on the same level as after the main competition, no major variations in the final standings would have occurred. In all of the studied six seasons, the first three teams finished always at the same positions.
The tables 1-3 show an interesting paradox. In the period of "dividing points" (seasons 2013/2014, 2014/2015, 2015/2016 and 2016/2017), the champion was always at the first or second place after the main competition. Only in the seasons 2017/2018 and 2018/2019, when all the main competition points were transferred into the after-main competition groups (and the main competition was supposed to have more influence on the final standings), the league was paradoxically won by teams who were third after the main competition. We can say that the motivation for stopping with the halving of the main competition points was de facto denied (at least in the championship group).
We cannot say the same about the relegation group. Although, even here, the halving of points impacted only on one team: Podbeskidzie Bielsko-Biała. In four studied seasons of halving main competition points, it is the only team that was relegated because of this rule. If the model 2 was used after 2013, they would not have been relegated (see table 6). In all other cases, the same teams finished being relegated.
Also Table 5 shows that keeping model 1 for all studied seasons would see the same teams being relegated -so it is true also for the 2017/2018 and 2018/2019 seasons (model 2 in reality). We can say that no major changes have been brought by the system modification.
The introduction of the after-main competition in 2013 did not bring any crucial modifications in the positions after the main competition. The results of this research correspond also to those of Pawlowski and Nalbantis [8], who analysed the Austrian and the Swiss leagues in a similar way, as both of these leagues use an after-competition system. Moreover, this research can identify with their conclusions that the more games are played, the less uncertain is the championship race. When the final positions of the Ekstraklasa after the main competition changed, usually, the winning team was the favourite one at the beginning of the season. Certainly, we can say this about Legia Warszawa. Up to Transfer Market [11], this team had through the analysed period 2013-2019 always the highest market value. Many authors [2], [4], [6], [12] consider the market value of a team as a correct expression of its quality and of its chances of success in a competition. Legia Warszawa was therefore, according to these authors, the main favourite to win the league, although only the after-main competition part of the 2016/2017 and 2017/2018 seasons helped this team to win the championship title.