Competitiveness amongst NBA teams is more constant throughout seasons than during the ACB basketball league (Spain), which also falls after every Olympic Games. According to a study from the University of Las Palmas de Gran Canaria, the differences could be attributed to economic and organisational reasons: in the NBA there is just one division, there is a salary cap and the weakest teams have access to good players.
The National Basketball Association (NBA) of North America and the Association of Basketball Clubs (ACB) of Spain are the best and most competitive basketball leagues in the world. But according to the work of researchers at the University of Las Palmas de Gran Canaria (ULPGC), equality between teams in the NBA is more constant year on year.
"The Spanish league displays more marked variations throughout seasons," states Juan Manuel Martín from the Physics Department of ULPGC and member of the team that analysed the results from the two leagues.
The fact that the NBA is a closed league with no category promotion or demotion, like in its Spanish counterpart, could be one of the factors that explain this behaviour. "The ACB is open and less powerful teams compromise the competitiveness of all member teams in general," outlines the researcher, who suggests the need to design strategies to change such a situation.
The authors also highlight the great budget differences between Spanish clubs, the high financial dependence on public institutions in certain cases and the high volatility of team members as possible causes. This can then be added to the fact that some are made up of different sections such as basketball, football and handball which do not receive the same resources each year.
"But what is really surprising about the Spanish league, despite not knowing the causes, is that competitiveness decreases every four years, just after the Olympic Games," states Martín. This is evident in seasons 1996-97, 2000-01, 2004-05 and 2008-09 after the games in Atlanta, Sydney, Athens and Beijing respectively. The researchers are waiting to see whether the same occurs after London 2012.
To carry out this study published in the 'Physica A' journal, the team studied the results from the regular phase of 14 ACB leagues (between 1996 and 2010) and 18 NBA leagues (between 1992 and 2010). Data from the last two seasons have not yet been analysed. The researchers applied a mathematical parameter known as 'Shannon's Entropy' to make their comparisons.
NBA was less competitive at 1990's
As for the NBA, the study confirms that competitiveness was lower at the end of the 1990's, decade of the triumphant Michael Jordan and the Chicago Bulls. "At that time the dominance of the Bulls was spectacular, but the league as a whole was less competitive and maybe this was also due to the increase in the number of franchises," as pointed out by Yves de Saá Guerra, another of the authors from the Department of Physical Education of the ULPGC.
However, the situation changes between seasons 2001-02 and 2006-07, which makes up the period of the most rivalry. These years coincide with the renegotiation of the salary cap, which is the maximum amount that each NBA franchise can spend on their players.
"It is likely that this has had an impact on the overall performance of the North American league, since the objective of the salary cap and other methods such as the draft is to avoid teams with large profits from getting all the best players. This in turn ensures equality in the NBA," says de Saá.
The NBA has a franchise model where each team has rights over their players. The salary cap and the draft (a draw whereby the weak teams get to choose their candidates from North American universities and foreign leagues first) makes each franchise carefully study which players to choose and which to sign under a tie-in contract.
According to the researchers, team performance is determined by two closely related factors: the level of players and finances. Without such measures in place, a large budget means that franchises could pick the best sportsmen thus perfecting balanced teams. On the other hand, those with fewer resources would tend to mainly pick those players that shine the least. As a result, in theory their teams are less compensated and would be less competitive.
The study also displays a fall in competitiveness for both leagues in the last two years analysed. "This is more accentuated in the ACB, possibly due to the economic crisis since access to resources is unequal," outlines Martín, who, in the case of the North American league, asks "Would the drop in NBA competitiveness in 2010 have anything to do with the strike in season 2011-2012?"
Explore further: Should a political party form a coalition? Voters and math decide
More information: Y. de Saá Guerra, J.M. Martín González, S. Sarmiento Montesdeoca, D. Rodríguez Ruiz, A. García-Rodríguez, J.M. García-Manso. "A model for competitiveness level analysis in sports competitions: Application to basketball". Physica A 391 (10): 2997, 2012.